Hello

3800 engine is interesting, good mpg with cheap price and okay acceleration at stock.


Ive read lots of tuning of this engine but i have not seen how about mpg?


So if i do basic: air intake, headers and mild cam. What happens to mpg?


And fast bonus question, do i need pcm remap/flash for those tune ups?

 

with a change of cam I would look are tuning.

 

depending on what you do the mpg can down, lol, more power more fuel.

 

I mean common, nothing specific camshaft on my mind.

 

There is a direct link between cam and tune. As the CAM profile changes it will change the dynamic of the air flow in the intake. A tune is basically a fuel map to match that air flow. Headers and intake improve the stock engines breathing so it reduces the lost HP caused by pulling air in and pushing exhaust out. So no tune needed. There are only a few Aftermarket grinds out there for 3800 cams and I suspect they will all hurt fuel mileage. Most tuners lean toward a fatter then stock tune (meaning more fuel) this means less chance of hurting the motor but less MPG. I think PCMs for less offers pre-tuned computers and they have tunes for most of the CAMs out there. If your serious give them a call, I am sure they can get you some real data.

My 96 3800 5 speed with a ebay intake and headers/flow master cat back got around 30 MPG on the highway. (Check my sig for the build thread) I even averaged 30MPG across full tanks of gas daily driving with mostly highway driving. I though the 5 speed version was kind fun to drive compared to the automatic version. On the highway aerodynamics is everything. Around town you are really limited by weight. It takes X amount of power to get 3600 lbs moving. Lighter cars do better around town, No one has ever accused a 4th gen of being light. All in all the 3800 T5 manual trans is an awesome combination. To this day If could not get a LS1 T56 my next choice would be a 3800 T5.

Also you could add a taller ratio rocker arm to open the valves a little more. Since the cam profile is not changing you should not need a tune.

 

thank you! So even with mild cam, stock pcm handles situation. Thats important to know because i dont wanna spend lots of money.



Im happ if 3800 with tunes goes about 28mpg at higway, 30 is very good.


Reason my intrest about 3800 is cheap price here in my country versus lt1 and ls ones, price is about half. And ive read that even stock 3800 in camaro gives pretty nice performance. With headers, intake and cam it will be more nicier.

 

My stock 3800 got 3mpg better mileage after I installed headers.

2.5" exhaust with cat and 2002 SS muffler before and after.