Very happy with my fuel Milage I got.

[bobjones003]

Well I know their has been a ton of these. I went for training with my new job in bloomington,il. I got 419.5 miles on one tank. It worked out to average 26.8mpg. I think that is pretty good for my car. It record for one tank on that car. Not the highest mpg. I had trip in the fall the car did 27.2 mpg. My older 92 bonnieville actually did better on long trip with fuel milage.My old 92 got crazy fuel milage as long as you did drive much of mi speed limit. My X-wife had the record she did 527miles on one tank. She followed motor home. I do think my 03 is more fun to drive on the highway then 92. My 03 never seems to be out acceleration. I am wonder what other people have got for top mpg or miles on tank with my body stlye?

[nos4blood70]

Nice! My record was 34 MPG. What kind of driving were you doing?

[zvega88]

i barely get 20 in city and 23 on highway on my 03 SSEI

[bobjones003]

I will have to try harder. That tank was about 75% highway. Generally on the the highway I drive 7-9 mph over what the speed limit is. I will try to stay at constant speed.Note zvega88 my car under normal driving around town get about 23 mpg in summer. Now that it winter it is doing about 21 mpg average.

[nos4blood70]

When I got that 34 MPG, there was no wind on a flat road, and I was doing the speed limit the entire way.

[zvega88]

I heard that my h2o might be bad the front one and that i might need to get a new one but like driving around city i barely get 310miles w full tank

[bobjones003]

So what is your actual mpg? Miles per tank it kind of hard to tell if the car getting bad fuel milage.

[zvega88]

Bobjones- it goes from 18 to prob 21. I'm don't get great mileage like y'all do. if I drive on highway it might hit 23 but I have tried to drive saving the mpgs and nothing.

[bobjones003]

Well I have never driven ssei but looking at what the epa guidelines for fuel milage on that car it look like you are in the ball park. 16 city 25 highway. But yeah o2 sensor(general if is complete bad engine light will be on). will cause you to lower fuel milage. Also worn spark plugs. Air filter. TIre pressue. Love of supercharge whine. Will all cause low fuel milage. Maybe someone else with a supercharger will chime in on what the get.

[Jrs3800]

I hate those EPA guidelines.......

My 03 SLE did a 28-29 average running near 80 Mph most of the way, and running only 87 fuel.. Did pretty good over the 4000 miles it was on the road in September... Had new stock GM Iridium plugs, new air filter, new fuel filter and a PLOG was installed in place of the front exhaust manifold...

In town the car is doing 22 Mpg...

My 95 Bonneville with the 97 PCM is averaging 26 Mpg mostly in town...

The 96-97 Bonnevilles with the L36 was rated for 19 City and 30 Hwy, The 00+ L36 was rated for 19 city and 29 Hwy iirc..

[MattStrike]

Based on what I've seen since the build (900 miles, so not much), the '93 SSEi (series II L67) is pushing 29mpg freeway, 23mpg putzing around. Same drivetrain recorded 30.5mpg in the LeSabre. And anybody who's ridden with me knows I don't go easy on it. I'd found that my peak mpg was somewhere around 68mph (LeSabre). The mileage on the SSEi was on an average of above 80mph (93 octane E10 over Thanksgiving weekend, with the hood scoop).

[terrancew3]

My car gets about 14 to 16 mpg city, and I think I go from 27 to 32 highway. I think the bad city mileage is because nobody around here seems to do a 30 in a 25, and I'm constantly slowing down and swerving around.

[00Beast]

Maybe it's time you stop going 30 in a 25, lol.

[MattStrike]

Does the TCC even lock at 25mph? I'm pretty sure mine doesn't until 30.

[Jrs3800]

On a newer 96+ the TCC can lock as early as 28 Mph in 3rd under light throttle conditions.. The trans can shift into 4th at 44 and hit TC lock at 44 as well..

And then you have PWM I and PWM II strategies... Both different and require different converters..

I have my 95 SE set up for 33 in 3rd and 45 in 4th... 26.xx mpg average

[terrancew3]

Maybe it's time you stop going 30 in a 25, lol.

The day I am forced to do 25 instead of 30, is the day I stop driving. Its sad when you see cops driving the main street (and many others) doing 30-35 in a 25. So usually I just use the fastest car as a lead/bait car.

[SPLLOUDER]

I noticed u wasted 20 % more gas by going over 65 mph say to 75 Mph .

either u get there fast and will your still young ,or u drive like grandpa and save some cents .

[bobjones003]

From experimenting with 92 Bonneville lower the rpms you go in the final drive gear the better the fuel mileage. On top that more constant you stay at that speed also helps. When I drive on typically I pretty much always be at 78 mph. Slower speed do get you better fuel milage.