Yukon MPG

Just curious, what kind of MPG people are getting with their Yukons, my last fill up, I was able to get 22mpg, that's with an 01, 2WD, on an all highway trip. I was pretty impressed. I was thinking of installing a K&N air filter to maybe give the mpg a little more boost. Has anyone tried this, or other tricks with the ever rising prices of gas today?

I have an '02 Yukon SLE, rated @ 14C/16H. I've gotten 15.2 MPG on my last road trip. Shocked about that. My Yukon has a 26 gallon tank. That's while running @ 80mph w/ A/C running. I'd like to know how you're getting more than that.

this trip was w/o running the a/c, last month on a trip NY to TN with a/c running, I averaged 19.5 consistently, w/cruise set at 65mph. If you have 4wd maybe that lowers your mpg?

I have a 00Yukon denali and run a CONSITENT 14MPG. Now, if I run 80, 85...it jumps up to maybe 15-16mpg...If someone is getting 20+mpg..please share the secret...hahaha

I have an '02 Yukon SLE, rated @ 14C/16H. I've gotten 15.2 MPG on my last road trip. Shocked about that. My Yukon has a 26 gallon tank. That's while running @ 80mph w/ A/C running. I'd like to know how you're getting more than that.
Granted that you were driving 80 w/ the A/C on, but unless your SLE came w/ a 6.0 engine (I doubt it but you never know) and/or you're running a 4.10 rear...you really should be seeing slightly better overall numbers than that. FWIW--if I can lay off the gas every once in a while, I can get anywhere between 15-17 mpg overall (17 if I don't run the A/C) in my DXL at 70 mph--especially given that my vehicle weighs 3+ tons w/ passengers and cargo, has a 6-liter engine, and rides on heavier-than-stock large wheels and tires.

Mileage is so subjective...many fail to post what gearing they have, engine size, 2WD or 4, towing package, etc. So here is mine:

I own an 04 Yukon 2WD with a 4.8 and 3.43 rear end with stock size tires. I have Gibson headers, K-N series 77 intake and a flowmaster muffler. After a lenghty break-in period (I use synthetic oil -takes longer to break-in) after 9,000 miles or so I got, and remain getting, between 17.4 to 18.3 consistantly in town. It now has 17,000. Highway drives, 75-80 MPH yeild about 21.5...not much more and worsen drasticly beyond 80 MPH+ (Its a small V-8 -more on this in a minute). Before 9,000 I was getting about 14 in town and 18 on the highway. Mileage improves once broke-in.

If I had a 5.3 it would do a bit better on the highway and a bit worse in town. Its a trade-off. I ordered the truck with the 4.8 since I dont 4WD or tow. In fact my truck does not even have a receiver hitch. But my in town (not really in-town since I dont drive in a typical stop and go; its somewhat mixed) MPG is great. I (my wife I should say) has a 2005 SSR 6.0 automatic with 3.73 rear that gets 15.5 or so in town but 24+ highway..so bigger engines (as I knew all along anyway) do better wound-out on the highway; they love to run. My 4.8 on the other hand; not as well on higher RPM's....they work harder=thus burns more fuel to propel the vehicle at high speeds. It's high school auto shop 101. Still holds true today. Many people think "Big SUV or car" or "Big engine" means gas hog (comparativley speaking) -not ALL of the time.

Thats why so often you see little jap SUV's and midsize SUV's dont get any better mileage (sometimes even less) than their large full-size counterparts ie-Yukons, expeditions, Tahoes. Certainly when it comes to highway driving or towing which lager V-8's are "more effecient" in this cenario. Again, big V-8's love to run and strech out on the highway -they were built for that.

Granted that you were driving 80 w/ the A/C on, but unless your SLE came w/ a 6.0 engine (I doubt it but you never know) and/or you're running a 4.10 rear...you really should be seeing slightly better overall numbers than that. FWIW--if I can lay off the gas every once in a while, I can get anywhere between 15-17 mpg overall (17 if I don't run the A/C) in my DXL at 70 mph--especially given that my vehicle weighs 3+ tons w/ passengers and cargo, has a 6-liter engine, and rides on heavier-than-stock large wheels and tires.


Can you actually get 15-17mpg. I have an 04 Denali short bus with 22's and I can't get any better that 14.9 on the freeway and 12.6 in the city. I also have a Volant intake and Corsa touring exhaust, but I still don't get anything near what you are getting. Does your DXL have the AWD and 6.0 engine? Do you run premium your truck? The only time I noticed a increase in MPG lately is if I ran premium in the tank and then I get an extra 1- 1.5 mpg.

This guy must have been coasting without the engine running to get 20+ MPG with ANY Yukon!

Hi,
please state year, model, short/long, engine, 2WD/4WD and rear axle ratio.

2001 Yukon XL (long) K2500 (3/4 ton, 4WD) 6.0 liter, 4.10 rear.
11.000 lbs 38 foot camper.
14 Highway
10 City
7.5 Towing in the flatlands.
6.7 Towing to the White Mountains in New Hampshire from Connectcut.
5.5 Towing up and down the hills of Connecticut.
Take care, Eggert :bananasmi

[This guy must have been coasting without the engine running to get 20+ MPG with ANY Yukon![/QUOTE]
No, but I'm no speed demon either,( I'm a very conservative driver) I drive 65 mph with cruise set, 2WD, 5.3L, not sure about rear end. I went for the 2WD, (wife doesn't drive in bad weather, do have TC though), with hopes of better MPG. From other posts maybe I was right. I have consistantly gotten 20MPG running a/c, Highway, and 14 to 17 in the city. The 22 MPG was W/O ac.

Hi redcar, I forgot to give my thoughts to your question.
There is only one optimal fuel to air ratio.
Any free flow air filter will let more air in so that you can burn more fuel to get more power.
As a side note, I have a K+N 'cold air' and do not like the added racket it makes.
I only use it during the towing season and then return to stock.
The factory air filter also is a 'cold air' system...
you can get a K+N filter for that, costs about $40 instead of the $250 for the full thing.
Take care, Eggert :bananasmi

I now have a 2000 denali 4w/drive that gets 16 mph hwy driving. One of my last trucks was a 97 gmc surb. with the 5.7. It would always get 19 to 20 mpg hwy driving. Have been a little disappointed in my new truck.

I get 30MPG with the 4WD on, in heavy mud.... ok, not really. Have an 01 XL 4WD 5.3, have no idea about the rear gears, and get max 17 on the hwy, usually between 16 and 17 doing 70.

I too have a great deal of trouble believing some of the high numbers above. GM has increased the highway rating lately, but not over 20 for sure.

I too have a great deal of trouble believing some of the high numbers above. GM has increased the highway rating lately, but not over 20 for sure.[/QUOTE]


.......What?! Are you serious? A 4WD I would bet does not get over 20 on even the highway...most vehicles described above are 6.0 liter XL's and 4WD. --Monsters. What else would you expect? But mine, a 2WD 3.43 rear and 4.8 liter (pussmobile) gets 21-22 highway if running around 70-75 no problem. In town average about 18. I varify this all the time when I fill up. I check and zero out the computer at every fill and I occasionally check the mileage against the receipt with a calculator. By the way, the on board computers (or calculators) are pretty much nuts on in my experience. In fact I'm very suprised and happy to see how accurate they are. HOWEVER the milage to go or RANGE feature of the computer seems abit on the conservative side...I believe they intentionally do this so you wont run out of gas. But otherwise the other features of the computer are accurate.

I have also done some performance upgrades that help the economy I'm sure. How much I really dont know.

Anyway mileage gets worse beyond 75 in my case. These trucks really could use a 5th gear to drop about 500-600 RPM..then we (I) would see something closer to 25 at these speeds. I run an annual trip from Az to Illinois and running on I-40 "out west" thru New Mexico you can really set the cruise on high. I ran once as I recall going about 85+ between Amarillo and Clines Corners NM and got about 18 MPG......but thats haulin' ass especially for a little 4.8. So yes I too have received mileage below 20 in this case.


Keep in mind guys that these things are trucks. They are not bought by the "fuel pinching" person. Thats why they have Kias. Also keep in mind they have the areodynamics of that found in a loaf of bread. They are bigger and heavier too. But pound for pound, the GM gasoline V-8 is very hard to beat in performance and combined economy.

Mileage is so subjective...many fail to post what gearing they have, engine size, 2WD or 4, towing package, etc. So here is mine:

<stuff snipped for brevity>

I (my wife I should say) has a 2005 SSR 6.0 automatic with 3.73 rear that gets 15.5 or so in town but 24+ highway..so bigger engines (as I knew all along anyway) do better wound-out on the highway; they love to run.
Perhaps so...but then again, a 6-liter SSR doesn't weigh as much as a long-bus Denali (SSR listed curb weight is 1000 lbs. less than a DXL), isn't AWD, and is a bit more aerodynamic--relatively speaking--than the DXL--all factors that can affect overall fuel economy.

Also, if bigger engines do indeed perform better (fuel economy-wise) wound-out on the highway...then why are the EPA highway mileage estimates for a RWD 4.8L Tahoe the same as that for a 4WD 5.3L Tahoe (both rated at 20 mpg hwy per Edmunds)? Yes--the 4WD 5.3L is roughly 200 lbs. heavier than the RWD 4.8L, and the drive type is different between the two, but I reckon the EPA figures on the 4WD weren't obtained while the vehicle was in 4WD mode, and 200 lbs. in itself isn't gonna cause a 1-mpg difference. So...if what you say is true, then why doesn't the 5.3L have better EPA hwy numbers? But I will agree with you on one thing you stated--mileage is indeed subjective, and can be "tweaked" by many factors...such as:

--What was the outside temperature? If you think your mileage was great even in 90-degree heat, imagine how much better it could be in 60-degree temps? Plus, in 90-degree heat, I betcha the A/C was probably running constantly...

--Speaking of A/C--and this is meant more for DenaliX5--I can get high 15's to 17 if I can force myself to not use the A/C. Living here in the Sacramento area during the summer, it is almost impossible to not have the A/C on while driving...especially when you have three small kids in the back. :iceslolan

--Yes, I'm running premium in my DXL, but that's because I have a custom tune designed to perform w/ premium gas; I could probably eek out a bit more if I could get my PCM tuned for higher octane since here in CA 91 is the highest widely available octane. Sure, that would probably explain why I could get decent mileage, but keep in mind that I swapped out my factory wheels and tires for a set that's 20 lbs. heavier at each corner. Unsprung weight can affect fuel economy--not a whole lot, but it can.

--Are your numbers based on a full tank of gas? From day one?

--Are you obtaining your numbers from the DIC, or by observing how much gas you actually pump into your vehicle? And even if your numbers are based in part on pump numbers--are you calculating based on when the pump nozzle first clicks, or after you top off? I mean, sometimes I can squeeze in almost two more gallons of gas after the pump nozzle clicks off, w/o having gas overflow out the nozzle. If I were to calculate fuel economy based solely on when the nozzle clicks off, I could cough up great numbers too.

--I can "tweak" my fuel economy numbers favorably by driving on roads with numerous and/or lengthy downhill grades. Case in point--if I drive home from Lake Tahoe (6000+ feet above sea level) to the Sacramento area (roughly 200 ft. above sea level) on a cool fall day in my DXL w/ no A/C and going no faster than 70 mph (except while going downhill, where it would be to your benefit to coast as fast as you safely/legally can, since you are not burning lots of gas while doing so), I probably could darn near hit 20 mpg overall. I mean, heck--if I build up enough speed on a good downhill grade, I can get the DIC to display an instant fuel economy of 99 mpg (and it would probably be higher than that if it weren't for the DIC display limitation)...now, how's that for excellent fuel economy? :lol2:

dacarter--yeah, I can get 30 mpg too...with a full load of passengers and cargo...while pulling a boat...with the A/C going all the time...while riding on underinflated tires...and a really dirty air filter...going uphill...all this while going into a headwind! :rofl: I'd be surprised if any all-stock 5.3L and larger-engined Yukon/Tahoe/Suburban/Denali could get 20 mpg hwy under normal operating conditions. A 4.8L RWD short-bus unloaded w/ no A/C perhaps, but a 5.3L? I'm not saying that it's impossible, but you'd have to have ideal conditions to get 20 mpg hwy out of a stock 5.3L SUV.

(Quote --Also, if bigger engines do indeed perform better (fuel economy-wise) wound-out on the highway...then why are the EPA highway mileage estimates for a RWD 4.8L Tahoe the same as that for a 4WD 5.3L Tahoe (both rated at 20 mpg hwy per Edmunds)? :


I dont know. The only Edmonds I know is the one who plays center field for the Cardinals.
I'm just saying that the bigger engines dont have to work as hard. I had an 02 Tahoe and a 98 Tahoe with the old vorec 350 and a 92 and 96 chevrolet pick-up and those F'ers all got (as I said in one of my posts) a bit better; 22 MPG for the same type of driving as does my modified 4.8. And yes my SSR is more arodynamic, but it also has a pretty heavy curb weight; a wopping 4700 or so LBS. with a 119 wheel base...its a GMC envoy on steroids really. It may have a LS2 Corvette engine in it and still does 5.5 0-60, but it certainly does not have the weight of that found in a Corvette.


(Quote--What was the outside temperature? If you think your mileage was great even in 90-degree heat, imagine how much better it could be in 60-degree temps? Plus, in 90-degree heat, I betcha the A/C was probably running constantly.)


Yes you are correct. AC running and the "thin", less dense air that is found in hot conditions will affect fuel economy (air to fuel density) as well. Cooler or cold days yeild better mileage all time, yes. So does going downhill in a huricane in nutral.

(Quote--Speaking of A/C--and this is meant more for DenaliX5--I can get high 15's to 17 if I can force myself to not use the A/C. Living here in the Sacramento area during the summer, it is almost impossible to not have the A/C on while driving...especially when you have three small kids in the back. :iceslolan )

Ya, tell me about it.....I live in Arizona!!!! No kids however thank God.



(Quote--Are your numbers based on a full tank of gas? From day one?)

Yes and yes.

(Quote--Are you obtaining your numbers from the DIC, or by observing how much gas you actually pump into your vehicle? And even if your numbers are based in part on pump numbers--are you calculating based on when the pump nozzle first clicks, or after you top off? I mean, sometimes I can squeeze in almost two more gallons of gas after the pump nozzle clicks off, w/o having gas overflow out the nozzle. If I were to calculate fuel economy based solely on when the nozzle clicks off, I could cough up great numbers too.)


Both computer and receipt calculations. Again, see my post on how close they both are. I ALWAYS stop at the first click. That is what I do my mileage on and no more. I was told along time ago to stop on the first click. Something about saturating the fuel line return causes vapor lock. So those are the figures I'm coughing up. Sorry, Im just reporting what I have.

--Yes, I'm running premium in my DXL, but that's because I have a custom tune designed to perform w/ premium gas; I could probably eek out a bit more if I could get my PCM tuned for higher octane since here in CA 91 is the highest widely available octane. Sure, that would probably explain why I could get decent mileage, but keep in mind that I swapped out my factory wheels and tires for a set that's 20 lbs. heavier at each corner. Unsprung weight can affect fuel economy--not a whole lot, but it can.

Well. Running premium and a custom tune and if your not using your A/C that would explain your increased MPG. As I stated before I have 22's with no custom tune and use regular gas. The average mpg I get is 14.9 on the freeway and high 12's running in the city, and I always leave my climate control on. With kids in the car, I'm not willing to turn off the A/C to squeak out a few more miles. I would rather be comfortable and not hear complaints from the back seat about the temperature.

I asked a few people in my area who own Denalis and they also state that they usually can't get much more than 15 mpg on the freeway and usually average 12 to 14 over all. These are people running regular unleaded and no custom tune but they do keep there climate control always on.

:2cents:

Just curious, what kind of MPG people are getting with their Yukons, my last fill up, I was able to get 22mpg, that's with an 01, 2WD, on an all highway trip. I was pretty impressed. I was thinking of installing a K&N air filter to maybe give the mpg a little more boost. Has anyone tried this, or other tricks with the ever rising prices of gas today?
I have a K&N Cold air intake that I just took off a 2004 YUKON when I traded it in as well as a MAGANFLOW Cat Back exhaust system that I need to get rid of. The Cold air intake gave me a solid 2 MPG increase. Anyone interested?

I'm just saying that the bigger engines dont have to work as hard. I had an 02 Tahoe and a 98 Tahoe with the old vorec 350 and a 92 and 96 chevrolet pick-up and those F'ers all got (as I said in one of my posts) a bit better; 22 MPG for the same type of driving as does my modified 4.8. And yes my SSR is more arodynamic, but it also has a pretty heavy curb weight; a wopping 4700 or so LBS. with a 119 wheel base...its a GMC envoy on steroids really. It may have a LS2 Corvette engine in it and still does 5.5 0-60, but it certainly does not have the weight of that found in a Corvette.

<stuff snipped for brevity>

Both computer and receipt calculations. Again, see my post on how close they both are. I ALWAYS stop at the first click. That is what I do my mileage on and no more. I was told along time ago to stop on the first click. Something about saturating the fuel line return causes vapor lock. So those are the figures I'm coughing up. Sorry, Im just reporting what I have.
I won't argue with you there, as far as bigger engines not having to work as hard as smaller ones. It would appear that even though they don't have to spin as fast to produce a given amount of power, they apparently still need to burn quite a bit of gas in order to do so...

And even though your SSR is still a pretty heavy beast, 4700 is nothing compared to 6000. That, and the fact that IIRC, the engine in the SSR is not the same as that in the Yukon Denali (correct me if I'm indeed wrong here); maybe not much of a difference, fuel-economy wise, but it is still technically an apple-and-orange comparison.

As far as stopping at the first click--if you deal with condomed nozzle hoses, you probably know that sometimes a nozzle click doesn't necessarily mean a full tank; the vapor recovery line (or whatever it's called) in the nozzle could be fouled up, thus causing a premature click-off. I mean, if I were to go off the click, there would be times where I could cough up numbers like 30 mpg... ;)

I know you said you based your calculations on a combo of the computer and your receipts, but the only "almost-guaranteed" (but not practical) way to verify fuel economy on a full tank of gas would be to fill a completely empty tank with a predetermined amount of gas, drive your vehicle until it runs out of gas, then calculate based on the number of miles you drove.

But yeah, trying to get decent fuel economy out of a heavy truck or SUV is a crapshoot as far as what works and what doesn't...

[QUOTE=tonytone]I won't argue with you there, as far as bigger engines not having to work as hard as smaller ones. It would appear that even though they don't have to spin as fast to produce a given amount of power, they apparently still need to burn quite a bit of gas in order to do so...


--Yes..Bigger engines have larger volume to fill (fuel/air) in the cylinders; bore and stroke and compression ratios and cam durations also factor into this. larger cylinders means more fuel intake. Its simple physics. There is, I imagine, a magic "displacement" for a perticular vehicle as it pertains to horsepower and how much consumption it requires to provide desirable performance with economy. But there is no such thing as a magic bullet, so its not ever worth discussing. They (large) are poorer in economy for in town MPG on this fact alone. They (pound for pound / displacement for displacement) do "better" on highway for this fact as well. We cant have it both ways --you know, the magic bullet thing. Hummm, if only engines could change there cyliner size????

[QUOTE=] And even though your SSR is still a pretty heavy beast, 4700 is nothing compared to 6000. That, and the fact that IIRC, the engine in the SSR is not the same as that in the Yukon Denali (correct me if I'm indeed wrong here); maybe not much of a difference, fuel-economy wise, but it is still technically an apple-and-orange comparison.

Yes you are correct in all statements. A bad comparision I agree. I really wasnt tring to compare, just trying to make a point. BTW the SSR (or our 2005 I should point out -the older ones were a doggy 5.3 liter pig that could barly get out of its own way -a GM disapointment) is a 400 HP all aluminum LS2 corvette 6.0 liter. A HUGE improvement over the "all show and no go" predecessors to the 2005 model. I mean this sled will do 0-60 in 5.5 and fly a 1/4 mile @ 13.something seconds @ 100+ MPH and will still daily drive around 15+ MPG in town on 87 octane...pretty good for a 4700 Lb. stock "truck" or whatever in the hell it is. But I love it.

[Quote]=] I know you said you based your calculations on a combo of the computer and your receipts, but the only "almost-guaranteed" (but not practical) way to verify fuel economy on a full tank of gas would be to fill a completely empty tank with a predetermined amount of gas, drive your vehicle until it runs out of gas, then calculate based on the number of miles you drove.

Yes. That would be a bit unpractical, but certainly accurate. Still, over a long period of time and calculating "averages" it's pretty damn close to real I would imagine. But why nit-pick this stuff?

I have an '02 Yukon with a 5.3 in it, getting 18 city and 20 on highway, I installed a K&N filter, that seemed to help some.

Depends who's driving.
I can get 18 or so, my wife seems to get 16-17.
One thing is for sure, when you hit the pedal to the metal you'll be seeing single digits if you're paying attention.
Still, it blows by most everythng on the road when you need it too - that's a big part of why we got it, as it certainly was not cost or value. Aslo consider full-time 4WD/AWD - that's asking even more.

The Good part: It's my son's chariot, wife's SUV, etc...

The Better part: My daily driver (S80) gets between 26 and 30 MPG, depending on how far I am going and how fast I have to get there. Had one road trip I averaged 32.2 MPG - and I can't complain about that :) ~M :smile:

I have a 2000 XL with an installed complete K&N intake (Ebay). I used to get like 17-18 on highway trips ... now I get like 20+. I always have at least 3 people w/ac on, BUT I only drive like 70-75mph. I think the slower speeds has everything to do with it. SO if you want to go from Tampa to Charlestown and still have 1/4 tank left, then take it slower!

Peace

Been a while since I added my original comments...

'02 Yukon SLE (2wd)
5.3L V8 (Flex Fuel Capable)
4L60E trans
3.xx gears (not sure... either 42s or 73s)
26 gal fuel tank
K&N filter (may buy FIPK)
Stock Exhaust (front to back)
Hypertech tuned (w/ PPIII)
87 Octane
A/C all times

My conditions include usual 75 - 80 mph on hwy commute, 100 mile round trip w/ approx 15 miles additional in city driving. Calculating my actual mileage is based on miles driven, and amount of gas consumed (not the tank capacity). On average I top my tank off with 23 gallons of gas, with a distance of 350 miles (on average) driven. That equates to 15.2 MPG (mixed area driving). I'm sure I'd gain a fraction more if the A/C was off, and if I dropped RPMs at or below 2K. I'm certain it's possible to gain a few more on straight hwy travel (ONLY). As for the 20+ MPG that was stated in an earlier post, that would have to be proven IN PERSON for me to believe. The EPA doesn't rate the '05 models that high, and they rate these higher than the average person will actually get. Not saying that anyone's wrong, but I'd truly have to see to believe. I hear rumors of higher octance, better mileage... that will also have to be proven to me IN PERSON. Seeing is believing. As for stock specs for the 2002 GMC Yukon (SLE) models with 5.3L V8s (FFVs), here goes:



Engines Size/Liters HP Torque Transmission EPA-rated mileage
------- ---------- ---- --------- ------------ -----------------
ohv V8 327 / 5.3 285 325 (@4K) 4-spd auto 14/18/16 (C/H/Combined)

4L60E Trans Specs (Yukon)
--------------------------
1st = 3.06, 2nd = 1.63, 3rd = 1.00, 4th = .70, Reverse = 2.29
Final Drive = 3.42:1 - 4.10:1

4L80E/85E Trans Specs
----------------------
1st = 2.48, 2nd = 1.48, 3rd = 1.00, 4th = 0.75, Reverse = 2.08
Final Drive = 3.73:1 - 4.10:1

Bottom line, I get what I get. No complaints. It's not a 4-cyl powered Honda (Accord's my daily driver... 28MPG of rated 30).

Holla back!

Rgloston--I still say you should be able to get a bit more than that, especially if most of the driving is freeway miles...and especially if you're running a 3.42 rear (I'd guess that you have the 3.73 rear based on your truck having the 5.3L engine). As mentioned in my previous post, I can get similar mileage even though my truck is heavier, AWD, and has the 6.0....and I still complain about not being able to get a bit more, based on some of the posts I've read in some of the other truck performance forums.

I have the '04 Denali, AWD., with the 6.0
SEFI w/ Displacement @ 364
Horsepower (hp @ rpm): 325 @ 5200
Torque (lb.-ft @ rpm): 365 @ 4000
Transmission: 4-speed automatic
Final Drive Axle Ratio 3.73
"Stated" EPA fuel economy, city/hwy (mpg): 12/16 or 13/17, depending on what resource you are reading

...That last line 12/16 is more like 14/17 for me, even 18 on a few areas of "flat land"; and I have not done anything to modify it yet. I have always gone K&N on my other vehicles and if someone with a config similar to mine has a suggestion that can get me an extra mile or three per gallon, that would be great.

I seem to get the best fuel economy ~ 80MPH, with or without the AC on...

When I hear about 20MPG+ from those like mlindberg, I wonder if this is the 5.3-liter V8, which was "rated" as 14/18 MPG. Even the "big" 6.0 available in 2000 only had 300 HP & 355 foot-pounds of torque, so it would likely get a mile or two per gallon better anyway?

To rephrase my inquiry: Who else has a (recent '04 or '05) with the 6.0 and can get this mpg level (19, 20, etc...) of fuel, economy? That's all I'm asking here - just about the '04 & '05 modles with the 6.0 under the hood.

What's the best value?
What is valid with the warranty?
These are the questions I am asking.

Again, I am looking at air intake systems first and foremost. Preferably those which do not require a dremel or other cutting tool to make it fit :)

I am hearing 2 to 3 MPG more depending on the system. If there are any exhaust options that "wow'd" y'all I would be interested in that as well. I love the ride, and I don't need it to sound like a Harley - or a riceburner :)

But if it gets me an extra MPG or more I'd be happy to

Sorry if I sound like I am repeating myself, just looking to get information that is relevant to what I have...

01 yukon slt. 5.3 4wd. pure roadtrip(all highway) is around 21mpg. averaging around 17/19 city/highway though. completely stock. i love it. i know jeeps that get 10x worse, stock... so what do i have to complain about hahah

I have an 04 DEnali shorty with the 6.0. I have 22's, Volant air intake, and Corsa touring exhaust on it. I'm thinking the intake and the exhaust cancel out the 22's as mileage goes.

I mostly drive in the city and get about 11.9 mpg. When I take trips I usually drive about 80mph on the freeway and get about 14.9 to 15.2 on the freeway. If I slowed down a little bit I may be able to get 16 or 17 freeway. No way anywhere near 20mpg.





I have the '04 Denali, AWD., with the 6.0
SEFI w/ Displacement @ 364
Horsepower (hp @ rpm): 325 @ 5200
Torque (lb.-ft @ rpm): 365 @ 4000
Transmission: 4-speed automatic
Final Drive Axle Ratio 3.73
"Stated" EPA fuel economy, city/hwy (mpg): 12/16 or 13/17, depending on what resource you are reading

...That last line 12/16 is more like 14/17 for me, even 18 on a few areas of "flat land"; and I have not done anything to modify it yet. I have always gone K&N on my other vehicles and if someone with a config similar to mine has a suggestion that can get me an extra mile or three per gallon, that would be great.

I seem to get the best fuel economy ~ 80MPH, with or without the AC on...

When I hear about 20MPG+ from those like mlindberg, I wonder if this is the 5.3-liter V8, which was "rated" as 14/18 MPG. Even the "big" 6.0 available in 2000 only had 300 HP & 355 foot-pounds of torque, so it would likely get a mile or two per gallon better anyway?

To rephrase my inquiry: Who else has a (recent '04 or '05) with the 6.0 and can get this mpg level (19, 20, etc...) of fuel, economy? That's all I'm asking here - just about the '04 & '05 modles with the 6.0 under the hood.

What's the best value?
What is valid with the warranty?
These are the questions I am asking.

Again, I am looking at air intake systems first and foremost. Preferably those which do not require a dremel or other cutting tool to make it fit :)

I am hearing 2 to 3 MPG more depending on the system. If there are any exhaust options that "wow'd" y'all I would be interested in that as well. I love the ride, and I don't need it to sound like a Harley - or a riceburner :)

But if it gets me an extra MPG or more I'd be happy to

Sorry if I sound like I am repeating myself, just looking to get information that is relevant to what I have...

The only way one could possibly get 20+ mpg out of a 6.0 is if the truck was going downhill for a good stretch; otherwise no combination of mainstream mods will get you that kind of economy under normal driving conditions while driving a decent number of miles.

Wow, Some mpg numbers are being posted...Just as a goff I figured out ours last month....we have the 2002 Yukon XL Denali with the 6.0....honestlywith combo driving around town and highway...10.4...ouch

2003 4x4 Yukon, 20s, stock - 14.2 every tank - I commute 25 mins each way to work + errands etc. Went to 16 when I drove 11 hrs, 1 way empty trailer, back with 2 bikes in the trailer and a wad of parts in the back. On cruize control set to 60 both ways milage was the same. I run regular unleaded.

'00 Yukon Denali
Vortec 5.7L; 4wd; tow package; 3.73 gears; stock wheels/tire size.

I get around 12mpg in the city and between 14 and 15 on the highway if I keep it around 70-75mph...any faster and the milage drops FAST

tonytone... My Yukon came stock with 3.73s. One can learn a lot with VINs. The only time I ran on a straight hwy trip, and ran it til the idiot light came on was when I ran a long haul from Jackson, MS to Atlanta, GA (Northside). Even then, I was running at 80mph the entire way, stopped a few miles past the GA state line to gas up again. Trip only showed 365 miles driven. I remember this because cuz my friend ragged me for buying a huge vehicle that got less than rated mileage for a single guy with no kids. Only put 24 gallons in tank when I filled up. Surprised that the idiot light came on.

At least I know how much fuel is left when the light comes on. My Yukon was completely stock from intake to exhaust back then. I later purchased a HPPIII, and saw no difference in mileage, but performance increase was barely present. I returned everything back to stock, and sold the PPIII. Building up a 5.3L to put in my '86 C10. That's my toy from this day forth. Going with a dyno tune, headers (no brand decision yet), Flowmasters (50s, 80s, or HP2s), cam & springs, and a 4L60E w/ high stall (probably a 3K).

rgloston--FWIW I ran the tripmeter after filling up for a relatively short <100 mile return trip from the SF Bay Area back home to the Sacramento area this past Saturday. DIC showed me averaging 16.9 mpg on the trip, w/ an average speed of 60 mph--even given that the majority of the return trip was done between 70-75 mph since it was mostly freeway (maybe around 10 miles of surface streets). 16.9 may not be much for a 5.3L but for 6-liter it is fairly impressive indeed, IMHO.

Yes, it is indeed. I can believe 16.9 MPG for a 5.3 and a 6.0. What I find hard to believe is claims of 20+ MPG on either of those engines (no matter what speed is driven). Though the 2003 & up 5.3s/6.0s (even soon to come 6.2s) have been EPA rated for 18 hwy, anything over 20 is questionable. I would have to see that in person to believe it. I would openly admit to being corrected, IF I see with my own eyes.

I think 20+ mpg out of a 5.3L is not entirely impossible, given some tuning mods to the PCM and ideal driving conditions (e.g., no cross/head winds, no hilly terrain, etc.)...but I agree with you that 20+ mpg out of a 6.0L near 3-ton truck/SUV w/o some kind of "cheating" is practically impossible to obtain. It's not completely impossible to get 20 mpg out of a 6-liter (a lot of things would have to fall neatly into place in order for that to happen), but I would definitely call BS on someone claiming to get that out of a 6-liter even though driving at no less than 75 mph for a few hours straight (no coasting).