SuprRunner

I normally do about 17-18 around town, 20 on the highway , about 300-340 miles per tank around town. My car has 230,000 miles on it.

The weekend, I went on vacation, and I changed my oil...I used the valvoline high milage oil(stuff in red bottle). I increased my timing to 14 degrees. I also have a stock filter.

Anyway, I was getting over 450 miles per tank on my trip, and averaged 25-26 miles to the gallon. That also includes several 5,000+ foot elevation changes

gsWarrior

i had a similar experience when i went down to socal a couple of months ago.

i usually average 300-350 miles a tank with normal city driving but on my way back from socal, i got to 432 before the gas light tank lit up.

i wonder if anyone has closed in on 500 miles a tank?

Wald GS

iTrader: (1)

Guess I'll ditch the mobil one and go for this! thanks for the input!

turbogs300

Changing from Mobil one to Valvoline is not going to give you any difference in mileage. Unless you change the weight, however unless you're using 20w-50 you probably won't see too much difference.

lexus4jess

dunno ,I like what I use now.he he

Wald GS

iTrader: (1)

On a sidenote, I have been getting crappy mileage with 76 91 premium as I switched from chevron 91. Does changing the oil not frequent enough have anything to do with it? thanks

turbogs300

As long as you're changing it at 3000miles for regular oil or when it gets dirty or dark colored for synthetic, you should be ok! Fuel economy is much more affected by the EGR system and the O2 sensors. As 02 sensors get old they can cause reduced fuel economy. Also your driving habits are very important as well. You'll definitely get better mileage with the cruise control set and maintaining a speed that results in the best gas mileage. Try some experimenting if you drive alot of highway miles with different speeds to find the most efficient speed. Check your plugs as well to make sure the electrodes are not rounded off. Running the AC also make some difference in fuel economy. In other words there are lots of variables.

Wald GS

iTrader: (1)

Thanks alot for the great informative thread!

So changing from Chevron to 76 gas really doesn't make any difference then?

thx

SuprRunner

Yeah, the oil may or may not have had anything to do with it. I will run a tank around town and see if I still get my 17mpg. If I get better, I will give the oil credit. I am just surpised to get such good gas mileage with 230,000 miles

lexus4jess

dead weight on your cars will reduces the mileage.boom box ,amps,rims will give you less mile.
"example" with my stock rims I got about 300 mile.with the 20"rims I had, I got about 220 mile.to the tank.

sillbeer

I recently got 27mpg on a road trip from Phoenix to OKC. From Phoenix to Albuquerque I clocked 22mpg. From Albuquerque to OKC I clocked 27mpg. The roads are long and straight without much elevation change. That was with the cruise on set at 85mph. For oil I use Mobile 1 synthetic 10w 30. All stock except for the griffin radiator and flex a lite electric fan.

-Destin

GenOneGS

I have gotten anywhere from 392 (least) to 435 (most) per tank since I've had my car, which has been about 3 months. BTW this is combined Highway and city driving and my car has 120,000 miles on it (1993).

CLASSLEX

WHAT oil weight are you using, and did the timing change help that much? I have a 95' with 135k and i don't get nearly that much milage unless it's all hwy, then it's like 350 per tank.

SuprRunner

Well, after driving it for awhile after I got back from my road trip, I now back down to about 20. Still better than my previous 17mpg. I am running a semi synthetic 20-50. I won't run full syntetic, especially with 230,000 miles. Not sure if timing helped. I will take it back town to 11 or 12 and see if I get worse. Somewhat hard to tell though. Sometimes I drive nice, sometimes I drive agressive, sometimes I drive highway sometimes I drive around town.

WHat I do know, is that in the highway alone, it rocks!

turbogs300

Wow! That's a bit thick for our motors, unless you have a turbo. That will cause some loss of fuel economy. Unless you have oil issues you really should drop down to a 5w-30, maybe 10w-40 max