I'm getting around 15mpg

[manicmechanix]

Originally Posted by bigbadbronxy2k5

OH man. I just calculated my mileage using this way: reset the odometer to zero @ fill up, fill tank to full and use Chevy's measurement of a full tank which according to my owners manual is 16.6 gallons. then drive till nearly empty and recheck odometer. 245 miles. That works out to 14.76 mpg. Ugghh .

No you are calculating it wrong. You don't divide the miles driven by full tank capacity. Instead divide by how many gallons you actually used and need to refill the tank. You never used all the reserve gas. My malidu has about a 16 galon tank, but even on E I've never put more than 11 or 12 gals at fillup. So how much gas did it take to refill your car? I'm guess it was close to 12 gals, so 245 miles/12gals=about 20 mpg. This is actuallt pretty good for a 3.8.

[bigbadbronxy2k5]

Originally Posted by manicmechanix

No you are calculating it wrong. You don't divide the miles driven by full tank capacity. Instead divide by how many gallons you actually used and need to refill the tank. You never used all the reserve gas. My malidu has about a 16 galon tank, but even on E I've never put more than 11 or 12 gals at fillup. So how much gas did it take to refill your car? I'm guess it was close to 12 gals, so 245 miles/12gals=about 20 mpg. This is actuallt pretty good for a 3.8.

Ok so using that theory, I put 13.3 gallons of Sunoco 93 in Saturday. That was full to a lil over F. So if I use that 245 mile figure I get 18.4 mixed city and highway. So if I do a nice trip and keep my foot outta it, I'll maybe get close to 22-23. Not bad I guess. Thanks for the correction.

[oldblu65]

Have you checked your air filter ? That can definitely affect your mpg and performance .

[bigbadbronxy2k5]

Originally Posted by oldblu65

Have you checked your air filter ? That can definitely affect your mpg and performance .

Well in my original post I stated I have all new filters, but it's a moot point now as I was doing the calculations wrong. My mileage is actually ok for the car it is. thanks for the tip though.

[garnold84]

My father-in-law did an experiment while on a road trip from utah to AZ. He found that chevron gave him the best gas milage. I have used chevron for the past couple of years on that theory. I don't keep as good a record of my mpg as I would like, but when I do calculate it I get about 19-23 city depending on how I drive.

Is it true that using higher octane fuels for cars that are supposed to run on regular will eventually ruin the engine (i.e.- the piston bearings ect.)?

[manicmechanix]

Originally Posted by bigbadbronxy2k5

Ok so using that theory, I put 13.3 gallons of Sunoco 93 in Saturday. That was full to a lil over F. So if I use that 245 mile figure I get 18.4 mixed city and highway. So if I do a nice trip and keep my foot outta it, I'll maybe get close to 22-23. Not bad I guess. Thanks for the correction.

Yep 18 mpg for mixed city/highway is normal for a 3.8. However, I think you might get a little better than 22-23 highway driving if you don't drive too heavy-footed.

Originally Posted by garnold84

Is it true that using higher octane fuels for cars that are supposed to run on regular will eventually ruin the engine (i.e.- the piston bearings ect.)?

No, where did you hear that?

[oldblu65]

bronxy ,my response was to the original poster (srmichi ) and he mentioned nothing about filter changes .

[Srmichi23]

Originally Posted by oldblu65

bronxy ,my response was to the original poster (srmichi ) and he mentioned nothing about filter changes .

i put in a K&N filter before winter and changed the fuel filter not to long ago.

Well changed from Exxon Plus to Shell Regular and now I'm getting 19mpg. I guess if i want to improve it more i could try not accelerating so hard and try my best to stop going after ricers that pass me on the highway