14.7

[marcre]

That's what I averaged per gallon my last tank of gas. I think I get the worst mileage out of anybody on the board.

My Rodeo is completely stock:
Tire pressure is perfect
spark plugs are less than a 1.5 years old
same with fuel and air filters
IMG is fairly new
EGR gets cleaned regularly as does PCV
Throttle body is clean
have a new O2 sensor at bank 1 sensor 2
bank 1 sensor 2 is less than 1.5 years old
both catalytic converters are "new"

I checked for brake drag, that's not the problem

I don't drive like I stole it, but I don't drive like my grandmother either.

I don't know where else to look.

I am not complaining about poor mileage because gas is expensive, I am worried there is a serious problem. I've had the Rodeo for two years and the mileage has always been bad. My mechanic says it may be the gearing, he wasn't sure about Isuzu and what they offered. Is it possible I have different gears from others who are getting better mileage? I doubt this is the case, but it is a theory at least.

The Rodeo runs great and I have asked this question before, I may even have a thread about this on here. Another won't hurt I hope.

I am at a loss, it just confuses me as to why I get this consistant, low MPG. I see post by all others on the Isuzu boards and it seems as if I'm way below.

Any ideas where to look?

marc

[amigo-2k]

all city miles?

[rodeo02]

Marc, that intake air temp sensor would do it. A dirty MAF will kill your mileage as well. I'd replace that IAT sensor if you havent, and I'd clean the MAF.

Joel

[Ramblin Fever]

Mine's hangin about 17mpg in city; I think it's the MAF sensor on mine that keeps tripping the CEL. It comes on for 2 days and goes off for 3, comes on...you get the picture.

Couple things, is the 14mpg all city? Lots of stop and go? If so, this could be about the best you'll get.

Another thing, has the rear differential fluid ever been changed?

[marcre]

thanks for the replies fellas.

a couple of things:
Rear diff has been changed last fall
I'd say mostly non stop and go with a lot of highway, but short trips.


Joel,
the IAC has only been broken for a month, bvut it does not effect the performance. It is broken in the outside housing, but the connector still attaches correctly.

I am going to clean the MAF, even though I do not want to touch it, ther are fuzzies all over it. It can't hurt, unless I break it, LOL.

I am seriously thinking I just have a vehicle that does not get good mileage.

The best I've ever gotten was 18, but that was once. Most of the time it is in the 15's to low 16's.

marc

[Gizmo42]

I was getting a steady 15mpg all winter. Got 16.5 on the first tank of non winter gas. The last tank I got on it a few times and was back down to 15 again. Mine is all just going to work and back (8 miles each way) but its mostly on I-225 so the same as city driving, only get up to highways speeds for 2-3 miles.

I dont remember what gear ratio mine has. Its printed on one of the tags bolted to the rear axle housing cover, if your tags are still intact.

Btw, I have synthetic in engine, trans, xfer, and axles. Didnt see any gain in mileage. But then theres no point in having 205 hp if you dont use it right?

I'll be doing plugs and cleaning MAF in the near future so will see if mine improves any.

[bishop242]

My 2000 averages 15 in the city... seems to be pretty average with this model.
could be the gearing, it was one of the the fastest suv's (0-60) in its class in 2000 and actually still is.
I average 22mpg on the freeway.

[amigo-2k]

http://www.albeedigital.com/supercou...0-60times.html

http://www.car-videos.net/performanc...p?id1=30&id2=0

[Ramblin Fever]

Macre - what oil viscosity are you running?

I agree with the idea that synthetics don't give any better gas mileage over regular fluids; but one viscosity to another will, i.e. 5w-30 versus even 10w-30. Reason for that, mainly in winter/cold season, is the 5w will get thru your engine faster and warm up faster when it's cold. There won't be more then a 1-2mpg difference though - but anything may help.

In temps above 50F, there's no difference in mileage gain between those 2 viscosities.

I threw in 5w-40 this last oil change, and my mpg has already dropped 2-3mpg; didn't experience this last summer though. But I think because the tune-up brought the mileage back up, and then I threw a heavy oil in it, and now it shows.

[Joihan777]

Hi Marc,
The best mileage my Rodeo Sport ever got was 22 mpg. This was on a
straight shot from Sacramento to Bakersfield..... a long boring flat surface.
The average speed was 65 mph with the top down.
However when I used to commute from Sac to San Fran Bay Area at 80 mph
I averaged 19mpg. I think speed & tire pressure made a difference.
BTW....... I assume your tires/ wheels are stock?
I do notice that she runs smoother requiring less foot right after an oil change.

[marcre]

I'm using 5w 30 pennzoil blend. I guess I'll have to learn to live with this, but it's annoying.

My main concern is that everything is OK.

marc

[marcre]

I got 17.2 on my last tank and 16.5 on the one before that. I hope it keeps creeping up, gas was $2.96 today. OUCH!!!!!!

[Blue Bowtie]

75W90 Mobil 1 synthetic Gear Oil in both differentials. Yes, the front one, too.

GM AutoTrak II in the NPG transfer case (the new variety "II" is also synthetic).

Do some tribology research, learn about polymers as VI enhancers, and you'll break your habit of Quaker State/Pennzoil for good. Try a more highly refined base stock oil like Valvoline or Shell. Or better yet, check into PAO synthetics instead.

Checked the alignment lately? Excessive toe can kill mileage.

Is the odometer correct? Oversized tires or a poorly calibrated speedometer can give the impression of poorer than actual mileage.

Is the EVAP system intact? And EVAP system that doesn't seal and recover vapors can lose 7% of its liquid fuel volume in a week in warmer temperatures.

Even though the cats are new, is the rest of the exhaust system intact?

[marcre]

Blue Bowtie,

Alignment was done in November.

The exhaust is mostly new, the muffler is original, but intact.

I use synthetic blend in the diffs as well as the transfer case.

Tires are correct size and correct pressure.

As far as the EVAP system, I don't know, but I have no CEL on.

The odometer is good as far as I know.

I use Pennzoil blend, I'd switch though. I have used Valvoline high mileage in the past, I may go back to it.


thanks for the reply,
marc

[Tom01Rodeo]

On vacation last month I got 20mpg. Usually, I bump the tire pressure up a bit, I think 28 lbs is too low (recommended). All synthetic fluids(Amsoil) including Series 2000 0W-30 oil year round.