getting BAD GAS MILEAGE (MGP) NEED HELP!!!

[wardak33]

hello. i just bought a 2002 Bravada with Electronic AWD (not always on, only on when needed). The car is in great shape except for the gas mileage. I don't know what to do. Any info would be great. I also heard that adding a couple ounces of Pure Acetone to your tank can increase your MBG dramatically. Please help me!!!

[wardak33]

Forgot to add that last night, i filled up the tank, and when i drove today for a total of 25-30 miles, already 1/4 of gas was used. is there anything i can do besides a K&N intake???

[GTP Dad]

Try replacing the O2 sensor especially the front one. If it is going bad it can cause the engine to use too much fuel. A lazy or slow sensor will not set a light either. Based on the price of gasoline the sensor is not that expensive especially if it saves you 2-3 MPG.

[old_master]

Acetone does make a noticeable difference. My 98 Blazer resulted in a 15% to 20% increase using a ratio of 5 ounces per 10 gallons of fuel. More is not always better, higher concentration tends to decrease mileage. Be very acurate when measuring, use a glass measuring device. Acetone will attack certain types of plastic and all types of paint and clear coat...you spill, paint is trash! I agree on the O2 sensors, all upstream sensors, (before the converter) directly affect fuel mileage. Oh, and save your money, use a good quality air filter and skip the K&N.

[Chris Stewart]

The old basic 35psi front tire/33psi rear tire pressures for the Bravada/Trailblazer/Rainier SUV's, new spark plugs and regular oil changes with driving the speed limit on regular roads & 60 to 65 mph on the freeway(70mph posted limit) saves a bunch of fuel.

With fuel prices so high, I can't joy ride much anymore so I leave extra early going to work and drive slow to get a short, "free" joy ride.

I don't like the K&N filters either..had oily dirt on the turbocharger compressor blades in my diesel until I replaced it with a huge paper filter.

[wardak33]

thanks for the tips...oil changes i might have to wait a month for. as for the spark plugs and o2 sensors, i can't really do them now because i'm a little busy, this is my first car, and i'm still in high school. the reason why i bought the car was because it was a great deal...but now i see why . just to note, the car does have 120,000 miles on it. and as far as the air intakes, can anyone tell me what a good brand is and is cheaper and better quality than K&N? any other tips would help too....thanks for the guys that helped already.

[ericn1300]

Wardak33 could you post your actual MPG without the acetone? Don't just go by the gas guage, they are notoriously inaccurate on the GM's.

Originally Posted by old_master

Acetone does make a noticeable difference. My 98 Blazer resulted in a 15% to 20% increase using a ratio of 5 ounces per 20 gallons of fuel. More is not always better, higher concentration tends to decrease mileage. Be very acurate when measuring, use a glass measuring device. Acetone will attack certain types of plastic and all types of paint and clear coat...you spill, paint is trash!

Acetone is a highly caustic, highly volatile liquid that has a high energy potential that will increase performance but will strip your engine of all residual lubricants right down to the metal pores, reducing the life the engine dramatically. It's also a known carcinogenic of much higher risk than Benzene, another gas additive in more common use and is much less stable.

I always wear a respirator when ever handling acetone, but you might want to check this out, they recomend a full hood: http://www.jtbaker.com/msds/englishhtml/A0446.htm

[wardak33]

The instrument which tells me the average miles per gallons currently reads 17.1, but i have a feeling that is not true. Yesterday, I drove it 25-30 miles (stop-n-go) and it had already used 1/4 of the tank of gas (which holds 18.7 gallons). That's almost at least 6.25 MPG. That's worse than what my 1999 dodge durango (5.2L V8 at 250 HP) was getting when i had it. and the durango got 9mpg city and 12 highway. This car has more horsepower, at 270 or 280, buts its a 4.2L I6 (inline 6)...man, i don't know what to do...

[old_master]

Eric, Here's a link to the "republican" version of Acetone use in fuel: http://www.pureenergysystems.com/new...00069_Acetone/

I don't feed my engine a steady diet of it due to the hassle involved, but on the occasional trip, I'll add it. Without a doubt it improves fuel mileage, and cleans EGR passages and the like, but as for performance ...never noticed any difference.

Wardak33, Cold air intake systems are nothing more than media hype. After all, how cold can the air get without a refrigeration unit? Engines run best with ambient temperature around 80 degrees Farenheit. Years ago the auto manufacturers used warm air intake systems to improve cold weather performance. Inlet air is heated in the intake manifold so the air/fuel mixture can be vaporized before it enters the combustion chamber. Advice is free, but in this case, it can save you money

[ericn1300]

Originally Posted by wardak33

The instrument which tells me the average miles per gallons currently reads 17.1, but i have a feeling that is not true. Yesterday, I drove it 25-30 miles (stop-n-go) and it had already used 1/4 of the tank of gas (which holds 18.7 gallons). That's almost at least 6.25 MPG. That's worse than what my 1999 dodge durango (5.2L V8 at 250 HP) was getting when i had it. and the durango got 9mpg city and 12 highway. This car has more horsepower, at 270 or 280, buts its a 4.2L I6 (inline 6)...man, i don't know what to do...

Don't expext much better, you didn't buy a Yugo, you bought a SUV. instead of dumping a bunch of money into quick fixes maybe you ought to learn to drive more efficently. That might get you up to almost 21 mpg on average: http://www.eartheasy.com/live_fuel_e...nt_driving.htm

[97TaurusGuy]

I highly agree on learning to drive more effeciently. There are lots of different "techniques" out there. 17MPG on a Bravada sounds about right. You can't just see how much the fuel gauge has moved in between trips to judge your MPG. Any vehicle I have owned the gauge seems to move faster or slower at different intervals. You should do an accurate calculation to see just what you are getting, you may be suprised. If you don't know how to do an accurate calculation reply back, yslef or someone else can tell you how. Also, K&N filters are over hyped. Buy a good quality filter (not Fram). You seem to be doing a lot of complaining about you MPG but when the other members post their suggestions you say you are too busy to do an oil change or spark plugs. This tells me that your vehicle must be far from properly maintained. If this is true, there's the problem most likely. Also, I found it interesting that you said this Bravada is your first vehicle and yet you talked about a Durango you had before.

[ericn1300]

Originally Posted by old_master

Eric, Here's a link to the "republican" version of Acetone use in fuel: http://www.pureenergysystems.com/new...00069_Acetone/

I don't feed my engine a steady diet of it due to the hassle involved, but on the occasional trip, I'll add it. Without a doubt it improves fuel mileage, and cleans EGR passages and the like, but as for performance ...never noticed any difference

You may be right. Many people try to tell me that I need to run “high octane” gas in my 1950 GM truck, but it's not actually the octane but the vaporization rate of the fuel being used. Check this out: http://www.bp.com/liveassets/bp_inte...ge_engines.pdf Older vehicles have less efficient carburation and depend partially on the fuel to vaporize at a predetermined rate. The vaporization rate of gasoline was higher in the days before it became more scarce and other byproducts such as acetone were distilled out of it but reintroducing a large range of hydrocarbons may actually defeat the design of modern engines despite their short term advantages, and by the way, increased mileage is increased perfomance.

Here's a link to why I'm no longer a republican, from way back before becoming an independent became fashionable: http://www.boiseweekly.com/gyrobase/...d=oid%3A154375

And another link to my view of Earth Day: http://www.boiseweekly.com/gyrobase/...oid=oid%3A2154

[wardak33]

wow, thanks everybody for your tips. the reason why i don't want to change the spark plugs or the o2 sensors is because i don't have that much knowledge on changing them, and i don't have the time or money to get them changed. as for the durango dillema, the durango was my mothers. i was driving it only until i had my license for at least 1 year to have enough experience to drive and own my own car. but thanks for all the tips. i know i sound like a woman complainin, but i'm just trying to find answers.

[wardak33]

This is what i plan to do this weekend. I plan to change the airfilter and see what how the o2 sensors and spark plugs are. I think they are in good condition considering the owner says he replaced them in january. other than the air filter, i plan to use a can of seafoam in the tank. i've heard good things about seafoam, but wanted to know what you guys think about it. People say it has more of an effect when it goes through the vaccuum line. I don't know how to do it through the vaccuum line though....is it easy???

and i've heard some bad things about seafoam such as ruining your oxygen sensors. I used a full can of seafoam through my mom's minivan and ia couple weeks later, i got code 171, meaning 1 or more o2 sensors went bad. so i turned it off. later on, i got 171 and 174, meaning ALL 4 o2 sensors, and upper and lower intake manifold. I know (to my knowledge) that the intake manifold has nothing to do with the seafoam through the gas tank, but what about the o2 sensors, can the seafoam be the reason? the van only had 81000 and its was a 2000, but it was also a ford....would seafoam help my baravada, and or ruin it?

[ZL1power69]

Originally Posted by old_master

Eric, Here's a link to the "republican" version of Acetone use in fuel: http://www.pureenergysystems.com/new...00069_Acetone/

I don't feed my engine a steady diet of it due to the hassle involved, but on the occasional trip, I'll add it. Without a doubt it improves fuel mileage, and cleans EGR passages and the like, but as for performance ...never noticed any difference.

i have used acetone on occasion also but the difference for me was only about a 1mpg improvement. i dont think it does anything for performance.
most of my driving is short trips around town so i get about 14mpg (which i think is a bit low).

a bravada has permanent awd so it will get slightly worse fuel economy than other 4x4 s-series trucks.