2000 SSEi. I filled up last night, reset the DIC and pulled into work this morning with it reading 27.8mpg.

My 97SSEi used to get 30Mpg, now its down to 26Mpg. Dont know why, I've tuned it, serviced it and I treat it good. Still runs great, just gets 4Mpg less than it used to. Now I tend to drive faster now. I commute a lot of miles, and average high speeds on the highway. I guess if I slowed down to 60Mph I may get 4Mpg more. Who knows.

I generally use Marathon or Amoco Premium or Ultra. I avoid Swifty and Speedway gas like the plague.

I average 400Miles out of a tank, but I always try and fill up after 300 miles. A few mechanics have told me that GM fuel pumps have a bad habit of overheating if you let the tank run low all the time, and they burn out early. And some of you know how much a new pump costs for these cars. I changed one in my 92 SSE and cost me a lot. Now my cars never get below 1/4 tank.

And my gas gauge on both Bonnies suck. My 92 shows empty when I fill it, then after 50 miles starts to behave. My 97 Gas gauge shows between 3/4 and Full at all times, and is never consistent.

Cheers,

O2 sensor may be going bad. Your mileage will drop before it gets bad enough to throw an SES light.

Yep, done that. Also done plugs, fuel filter, PCV, air filter. Tranny has been serviced and flushed. Running 180 T-stat. I am out of ideas there. But its ok, I can live with 26. As long as it doesnt go lower.

ok so when my dad went out to buy it and drive it home he said he threw in $10 in gas and didnt do premium....... WILL THIS CAUSE THE SSEI TO EAT UP THE REGULAR GAS? someone please say yes.... and dont lie. this poor mileage is getting way out of hand.

Decent running SSEi + 87 octane = POOR MPG!!! (would be excellent running with 91+ octane fuel)

SSEi needing o2 sensor, TPS, and plugs + 91+ octane = 13-15 mpg (in my case)

Freshly tuned up (still need TPS) SSEi + 91+ octane = 27 mpg (in my case)

oh ok thanks.. for a day or two i thought id have to give up this god send of a car.... i love it.... i will try the expensive as hell 91 octane to see how it runs now...... how about racing gas (104 octane) i know w place here where its relativley cheap haha. thanks

Is it the Holiday on Central Ave about 1 mile south of 694? I bought my Lebaron TURBO GTC Convertable at the dealer right across from there back in 8/99 and they had 104 octane for like 10 cents more per gallon than for premium. They also had 110 (which kinda surprised me as usually it'* only one grade of racing fuel at one gas station, and not two). I think the 110 octane race gas was 25 cents over the 104.

its in north st paul, around where they have the old car nights in the streets. somewhee around there....

but what will 104 do to the ssei?