So what performance mods help gas mileage?

I know the u-bend delete will, as well as some other exhaust mods.

But what specifics?

How many MPG can be gained?

Will it pay itself off if gas is 2.00-2.15 a gallon?

Never worry about MPG's.
And gas down here is $2.40 for Prem.
Feel lucky.

That's a pushy subject. There are many possibilities for a "econ" mod. Most mods are economic. I wont even begin to start but lets say Intake, pcm, Spark plugs, Ignition sys., Exhaust system. blh blah blah. No accurate way to tell you a MPG saved either. Soo many variables. Im sure there are a few members that can help you out

Thanks..

Well I am asking because I may get my dad to pitch in if it helps my mpg enough...if I do anything at all...

Not thinking about real big internal mods or anything...more intake, exhaust stuff...pcm-not sure how much stuff like that runs but it could be a possibility...

Also if I do a CAI will that help my engine as well (I hear it helps mpg but I could be wrong) since it keeps it cooler?

I noticed a 3 mpg increase in mpg on the highway. City was unchanged. The hardest part of mpg increase with mods is you tend to put your foot into the pedal more after you've modded.

I only saw an increase in MPG when I did a full tune up at 75k miles.

I see much better mileage when I use Chevron 89 octane versus 87. And when I use cheaper gas, like from 7/11 (been a LONG time since I used that crap) I notice the MPG falls way off. I've got mods that both help and hurt fuel economy, but for sure the intake, downpipe, UD pullies, ported TB and exhaust manifolds help mileage.

Would a fuel filter affect mileage at all? I've done a full tune up other than the fuel filter, which is on the long list as soon as I get a chance. I guess I should do that soon, eh? With 122K on the thing. Anyone know how long these motors last, I'm starting to worry now that I'm getting closer and closer to 150K.

I'd change it. I need to change mine this weekend.

I have a friend that had an 89 Regal GS with the 3800 (obviously earlier version), and he had that thing up to like 350k+ miles, but that may be a rare happening...
I would suspect they most will last up to and past 200k


as for mods adding mpg, I think most bolt on stuff like exhaust and intake stuff, will add mpg IF you are easy on the accelerator. Other mods, such as cams, obviously decrease mpg

There are GPs with the series 2 3800 running around with well over 200k.

3800 is a solid motor.

It's solid as long as you take care of it.

The fuel filter is one thing that can do a lot of damage to gas mileage. They get gummed up pretty quickly. Change it every 30k.

High octance gas will get you better mileage because of the way it burns.

Tech the best thing you'd want to do if your just interested in MPGthe cheapest way for now is look around for a Econ Chip, clean airfilter, and keep your foot off the gas, But a pedal bike, your feet, Or con a freind into giving you rides is the #1 gas saving technique

Based on what everyone is saying plus my $0.02, here is how I would answer your question.

Before thinking about modding, consider the two main things: Maintenance and driving habits.

Fuel and air filters should be changed on a regular intervals. Don't skip on oil changes either. Don't drive hard but coast on occasion and don't go way above the speed limit on highways.

100% argree with GTCombination's suggestions. There is nothing like having an extra $10 bucks in your hand from savings.

If MPG is the only concern, I recommend leaving the car as-is i.e. no mods.
Last option is "invest" in an ol 4 banger.

Only if your car calls for higher octane. Otherwise your throwing money away. Another tip is to keep your tires properly inflated.

Guys, really I am not JUST looking for MPG.

I drive lightly as it is...for the most part, there are times when i like to accelerate nicely just for fun...i mean its not rare that I do this, but I usually am at the speed limit + maybe 4-5 mph...

I would like performance, definently, but seeing as to how i dont NEED it I think some MPG incentive may do the trick for when I just drive around regularly.

But I have read that CAI's keep your engine nice since the air is cooler, so I think that would be a good thing.

I don't even think about gas prices. What are you going to do? stop driving? Yeah right, its just one of those things you have to pay for. I always stomp on the gas, I tried to drive nicely and get good mileage but it just didn't work so I gave up.

LOL if your worried about mileage buy a little Ricer,and yes change your fuel filter on a regular basis ,as far as premium fuel goes in a GT unless you have an aftermarket PCM do'nt waste your money as it wo'nt effect mileage or performance butif you are modded by all mean use the highest octane available ,as far as longevity on the 3.8 with proper maintanence it good for around 200k or mayby more they are a tuff little motor ,why do you think GM has kept them around for so long ,Later Chico.

I had a 1989 Olds 98 Regency with a 3800 engine. It had 270k miles when I gave it to my younger brother. It was still running good when he gave it to our cousin.