99 GT Fuel Mileage

[RABS]

3.4L.
V6
I drive it ok, not rough and do not really race.

Just changed the plugs (Bosch Plat) and did the oil for the winter (5W-30) as well as the air filter.

On a tank of gas how many Km's should I be getting ? Right now it in the low 300's. I'd like to get it up to the high 300's or maybe even get into 400's.

What else can I do to improve the gas mileage ???

[99blackSE]

make sure the tires are properly inflated...
do a search, there should be some more stuff about this somewheres...

[sunrunner_pei]

YOu should easily be in the high 300's per tank. Has all the regular maintenance been done? Air filter, fuel filter, PCV valve, etc? Were you getting better mileage before the Boshe platinums?

[voyager]

this will be a long post because i think about this stuff alot..

what kind of driving do you do? if you're taking short trips, in traffic, in city, lots of stopping and starting then your economy will be much worse than longer trips at constant highway speeds. 300km ( ~ 180mi ) is terrible for a whole tank of gaas, but what are you calling a tank? 10gal ( 38 litres )? you need to divide your distance by your fuel consumption and come back with an km/litre or mi/gal number. " how many miles per tank " is meaningless without knowing at how much you are putting in the tank and what kind of driving you are doing. you should be between 8.5 to 12km/l depending on driving habits.


i can go 725km on 53 litres of fuel on the highway, or about 500km if i am driving about the city. i do better than most, but i have some modifications that help.


check tire pressure, PCV valve, exhaust components; make certain plugs are properly gapped, replace fuel filter, clean TB and EGR passage, toss in some injector cleaner, DO NOT use high octane gas and remove the 600lbs of sand from your trunk; accelerate slowly, coast when you can and try to keep a constant speed; stop towing boats.

oversized rims will hurt your economy, as will heavier rims ( most popular aftermarket rims are heavy ). using A/C ( this includes the defrost setting, which uses the A/C pulley ) or driving over 45mph with the windows down will hurt your economy. giving your friend 'fat tony' a ride will hurt your economy.

a park bench on your trunk lid is a terrible idea and only increases drag. i don't know if you have any sort of modifications, but stay away from big heavy wheels, spoilers and stereo speakers if you want good economy.

different gas stations give different results. i have good results from shell & exxon, poor economy from citgo, conoco, QT and most off names. chevron & texaco are average, not the best but better than most. i prefer gas with an additive.

i don't know if your transmission has an OD ( 4th gear ) setting, but using it on the highway dramatically improves my fuel consumption as opposed to D ( 3rd gear ). generally the lower your RPM's the better.

you need to drive a car on the highway every once in a while for some miles to help burn out carbon deposits. if all your driving is less than 10 miles at a time, go for a 50 mile trip a couple of times a month.. it'll help a little, but a bunch of short trips will give you poor economy no matter what else you do.

[Fastlanev6]

well said....that post looks familiar....did I see it on bstuff too? lol.