Flame me know or later; tried to search but ran out of patience.

Wanting to know what everyone is getting as fuel mileage out of there 3800 SC swaps??

Will decide the fate of my fiero pending MPG more then likely.

thanks......

3800 SC II with the 4T65E-HD tranny on an 86 GT with Finale body conversion. Fairly stock set-up with headers, good cold air intake, decent tune, about 240w.h.p. I drive about 80 to 150 miles most weekends to shows, parks, a little street fun, etc. Get on the gas maybe 25% of the time when driving with a combo of city and highway driving. I've always kept gas logs on all my cars. This car is averaging 25.4 m.p.g. per tankful since March. Worst winter average tank was 22.3 (our winter formula gas stinks). My best city to city highway trip got an average of 34 m.p.g. These are all numbers right out of my gas logs. Just curious, looking at different swap mileages?

[This message has been edited by Darrelk (edited 06-22-2008).]

With my most recent timing table adjustments, I was able to acheieve 33mpg on a 90-mile highway trip. If I drive regularly, I get around 27mpg.

I run the 4t65e with 2.93 gears.

------------------
'88 GT- 257rwhp 319rwft/lbs 12.74@106.2mph 1/4 mile

quote Originally posted by Darrelk: 3800 SC II with the 4T65E-HD tranny on an 86 GT with Finale body conversion. Fairly stock set-up with headers, good cold air intake, decent tune, about 240w.h.p. I drive about 80 to 150 miles most weekends to shows, parks, a little street fun, etc. Get on the gas maybe 25% of the time when driving with a combo of city and highway driving. I've always kept gas logs on all my cars. This car is averaging 25.4 m.p.g. per tankful since March. Worst winter average tank was 22.3 (our winter formula gas stinks). My best city to city highway trip got an average of 34 m.p.g. These are all numbers right out of my gas logs. Just curious, looking at different swap mileages?

Looking @ mileage to see if I wish to pursue 3800SC. MPG's look pretty sweet for commuting highway. Yes, I do want something I can get into tohe pedal every now & again & know theres something to have a little fun with

Yeah, these motors are just loafing along on the highway when in overdrive. Around town there just idling along most of the time, too, well until you stomp on it! Lots of fun... and I can still afford to drive it.

quote Originally posted by Darrelk: Yeah, these motors are just loafing along on the highway when in overdrive. Around town there just idling along most of the time, too, well until you stomp on it! Lots of fun... and I can still afford to drive it.

Did you do your own swap or ????

Tuning on these setups will produce huge gains in gas mileage... A baseline of 30 mpg is not hard to obtain with a bit of tuning work. Some of the grand prix guys claim to get high 30's somehow.

Brimmy, mine was one of the early swaps done by Ace Engineering completed at the end of 1998. Motor and tranny were a 0 miles combo directly from GM at the time. Car has been running great with this drivetrain for about 70,000 miles now.

quote Brimmy:...Wanting to know what everyone is getting as fuel mileage out of there 3800 SC swaps?? thanks......

Most of the above swaps involve the tranny as well, without which, the numbers would be much lower.

I have a 3800sc II with the Fiero 5 speed getrag and I've been getting 33.5 on long trips 27 around town.I have a
hot cam, cold air intake ,custom 2 1/2" exhaust, 268 WHP on the dyno 286 torq.

man something is out of whack with my car. last summer i got around 30 and now its 20-22. i need to get some time to figure out the deal.

last calculation was about 27 in town and just under 32 on the highway. 5 spd, 3.2", XP cam.