LT1 Gas Mileage

[alone_and_insane]

I know a guy's interested in a 4th-gen Firebird, probably 6-speed LT1. What kind of gas mileage are you guys getting with that? Also, what exactly is the difference between a Formula and a Trans Am?

[my95z28]

I got 23 mixed with my 95 6 speed. 27 Best on the highway. Differences between a Formula and Trans Am are front and rear bumper, and the side skirts.

[JoeliusZ28]

ive gotten a best of 33 with my LT1 (had headers and a CAI) and a worst of 12mpg.

One time i got 19mpg on a tank with 6 track passes... cammed too!

Put an LS1 lid and longtubes on a stock LT1 6 speed and i bet it will hit 35mpg on the highway.

[MunsterZ28]

man something is wrong with my car. i get like 15mpg with my 6speed. and i drive it normal without beating on it.

[JoeliusZ28]

theres a LOT wrong with my car...

[MunsterZ28]

theres a LOT wrong with my car...

lol if your bored drive over to my garage to see a real pile

[93formulalt1]

I know a guy's interested in a 4th-gen Firebird, probably 6-speed LT1. What kind of gas mileage are you guys getting with that? Also, what exactly is the difference between a Formula and a Trans Am?

Differences between Trans Am and Formula- Front and Rear Bumpers, Side skirts (T/A has skirts, Formula doesn't), rear spoiler (T/A has high-rise spoiler, Formula has the same one as the V6 Firebird), and I think that's it. They both had the same grid-style taillights. T/A's had fog lights, Formula's didn't. IIRC, the Formula is actually a little bit faster stock-for-stock vs. a T/A, but that's due to the weight difference (I think it's a negligible difference). Same engines/transmissions, same suspension, same everything except appearance. Formula's are FTW though, they look like a V6 car except for the "Formula" decal on the rear bumper. 1993 decals said "Formula V8", 1994 and later Formula's just had "Formula" on the rear bumper.

As for gas mileage, I've been getting pretty bad gas mileage with my LT1/700R4 Formula, but I beat on it a little more than I should, and I think my fuel pump is going out. . . I think I get about 16-18mpg city, and I don't do a whole lot of highway driving, but I'd guess I'd get about 23mpg Highway. 6 speed is definitely the way to go if you're looking for better gas mileage, those two extra gears work wonders for the economy of the vehicle!

Hope that helps!

[nascarnate326]

Havnt did any real testing, but so far its not looking good for MPG on my car.

[SoulTerror]

Put an LS1 lid and longtubes on a stock LT1 6 speed and i bet it will hit 35mpg on the highway.

I really need to look into this LS1 lid.

I have no clue what MPG I get because my car died after only having it 4 days

[98blackbeauty]

I don't beat on mine normally 3K granny shifts and I get 15-17 MPG around town. I only have headers. I get 22 -23 MPG on hyway. Lot of my driving is 45 50 mph I don't use 6th gear car seems to sluggish at 50 in 6th.

[SoulTerror]

Never mind about the LS1 lid, stock hood won't work unless I cut it up from what I read. Maybe one day when I get a ram air hood.

[nascarnate326]

I don't use 6th gear car seems to sluggish at 50 in 6th.

I have the same issue.

At 50-55 I feel like 5th revs it too high, but 6th is too low.



I need to seafoam my car. I bet it would help, it did on my v6.

[prorac1]

I do a lot of short trips with my car. But I get around 24 mpg on long 2 lane trips. I shift at 2,000 rpm. I even shift into 6th at 2,000 and dont have a problem. Dosent seem to sluggish to me.

[93formulalt1]

I have the same issue.

At 50-55 I feel like 5th revs it too high, but 6th is too low.



I need to seafoam my car. I bet it would help, it did on my v6.

I seafoam'ed my car once, it seemed to help out a TON for a little while. I'll do it again after I get the headers installed. I'll probably be replacing my fuel pump this summer too, so hopefully that will help my fuel economy at least a little bit.

As far as the LS1 lid mod, I'm SERIOUSLY considering it, it seems like a pretty good improvement, I'm just a bit apprehensive about cutting into my core support to do it. . . Not to mention, I'm trying to avoid spending too much more on the car this year, money is going to be pretty tight until I get a better job.

[freakshow]

Difference between a Formula and Trans am, Trans am is way cooler looking. Gas mileage sucks, but thats not why we drive em.