GM 3.1 liter using excess fuel..?..

[BoxMN]

Another 98 Malibu with 3.1 question 130k miles, running what I think is good.

It is getting 20 mpg driving from WBL to St. Paul, mostly city driving into downtown, so not really driving that should get good mileage. But I recall wife getting about 23-24 in the past.

I put on new rear strutts, new rear tires, and had it aligned at a shop. He gave me the rack printouts and all, though not sure what it all means. I even had to buy some type of adjustment extensions so he could get it into spec. Was told by others that this is common. Just noting this as the strutts and alignment were the only things I have really done. Not noticing any wear on tires and steering wheel sits nice and center.

I was kind of expecting my mpg to increase a bit. But I guess maybe A/C and city driving can account for the drop?

I pulled the vacuum off the fuel pressure regulator (put new one on a few years ago) and no leaking, and vacuum is working. Not sure what else to check. Maybe all is well? just wondering if I am getting to picky and concerned, as the car runs, drive and starts well. I was just expecting a bit better mileage after the alignment. Maybe I need to take it for a 50 mile highway test, as I know it can get 30mpg going 55 with few stops. Thanks.

[Macgyver55]

Unless your alignment was WAY off (enough for extreme tire wear) I doubt you would see any measurable change in mileage after an alignment. A/C will definitely lower your mileage somewhat.

[Eric Wettschreck]

My son has a 96 cutlass with the 3.1 motor. He was getting only around 14 MPG and the thing had absolutely no power. I tried and tried and tried to figure out the problem, and just didn't get it.

Not very long ago I was checking all the fluids in the car and the radiator was pretty much empty. I remembered that I had filled it not too long ago. I started putting 2 and 2 together. The 3.1 has a reputation for blowing head gaskets, and both of his are goners.

I found a low milage motor at a local scrap yard for not a ton of money so that's the route we took. A weekend worth of wrenching and he has a way fresher motor, MPG is good, and the thing actually acclerates without putting the foot feed to the floor.

Not saying your motor has the same problem as my son's had. Just tossing it out for discussion.

Added bonus for me, my back and forth to work car is a 96 Lumina with the same motor. I may (emphasis on may) overhaul the one we took out this winter and drop in my Lumina as my Luminas starting to get kind of tired. 245,000 will do that to a motor.

[BoxMN]

Thanks guys.

I just did the intake gasket last year and no leaking cool anymore. So hopefully engine is still in decent shape. Maybe 20mpg for how she is driving it is okay, since mostly city, but I was hoping for about 23-24.

Knock on wood, its' doing okay and riding pretty much like new after new strutts and tires. Have a great weekend!

[BoxMN]

I got my answer. I finally took it for a short teston highway. It is getting about 30 mpg with A/C going, but just on short test so far. So it looks like the 20 is just due to the city driving, and the car is fine Thanks.