I am only getting about 20-22 on my SSEi. I thought the gas mileage would be better.......something happens when I see that little BOOST gauge move and my lead foot kicks in and whomp!

Yea that right foot is the killer. The thing that gets me is that wonderful whine that is emitted when you get it above 3500 rpm. That and the surge when the power hits the ground...... I thnk the best I have gotten was right after I got the new spark plugs I got about 35mpg. I may be fretting since I averaged about 50mpg in my grand prix on a trip up to my grand parents(trust me it was fifty. The tank wouldn't take anymore gas when I filled about 2 hours into the trip(a 4 hour trip)). On the way back I had my dad with me we were going into a strong wind that day and I still got about 42 mpg. That might be why I am not used to it......

Not saying it didn't happen, but I find this very hard to believe..and I am a guy that was able to get 32.xx mpg in a 1999 Trans Am on a 500+ mile trip with people not believing me, so I know what it is like to have people not believe you when you get amazing mileage..but 50mpg and 42mpg against a strong wind...that I am having a hard time believing..

If somehow the car did it that is beyond amazing...but no way can you expect that out of our cars that are rated at like 20 city and 29 highway..

I believe him. I once got my Avalanche to do 25 MPG on the highway.

Mine seems to net about 21 mpg (mostly highway), a bit shy of Pontiac'* estimates of 17/23.

Why? Does anyone remember that old car commercial with the guy with the actual lead foot? That'* me. No supercharger under my hood, but the opened intake gives a good roar around 3000 RPM…

I've had 34.6 mpg average on a 1,500 mile trip. 70 mph most of the way. On the same route (different trip), a headwind knocked me down to 28 mpg hwy. In town I get around 19 mpg, but lots of starts and stops and plentiful hills.

What'* the mileage on your car? I've heard that oxygen sensors should be changed after 50,000 miles. They might have an effect on your mileage, I don't know first hand.

Personally, I think that the ethanol they're putting in the gas now decreases mileage. My mileage seems to have suffered lately too.

Yes it does. I found about a 12% drop in mileage when using E10. Now, this is a small data set with only 2 tanks of gas. But both times I had about the same drop. Now all I can get is E10

Yes, E10 will drop your mileage since the ethanol has less energy (Btus) per gallon when compared to gasoline.

Matt

Well that is believable...My Dad got 24 in his silverado on several occassions.

24mpg hwy in a vehicle rated at 19-20mpg hwy is achievable and believable in ideal conditions.

I am saying 50mpg in a vehicle rated at 30mpg hwy is a bit harder to believe and 42mpg against a head wind in a vehicle rated at 30mpg is also hard to believe.

My 96 Grand am with the 3100 V6 was able to get 36mpg on interstate trips in perfect conditions...how could a grand prix that weighs at least 500lbs more get almost 15mpg better? not seeing it.

If he was able to get 50mpg on MANY occassions then okay..he had a freak car..but for him to have got it on one trip...there are too many variables to find it legit..

Anyways, this topic was about his mileage in is Bonneville, and from what it looks like he is getting right about what he should be for his driving.