I have a daily driver 1987 SE - 4cyl, 5pd with 216,XXX miles on the original motor, and I was always curious of how many miles I could drive on a tank of gas. Yesterday, I broke the 300 mile barrier - 307.8 miles on 9.7 gallons of gas.

Prior to filling up, the gas tank needle pretty much indicated empty, though I probably had about 2 more gallons of gas left in the tank (87 and 88 Fieros have 11.9 gallon tank). At about 32 mpg, I could probably break the 350 mile barrier. What's your ride (engine and tranny), and how many miles are you getting per tank? I believe 84-86 Fieros have a 10.2 gallon tank. - kv

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88 GT T-Top 5-spd #338 of 1252
87 SE 4-cyl 5-spd sunroof, spoiler, performance sound
85 2M4 base coupe T-Top 5-spd, rackless decklid, 15-in 88 GT rims, aero-conversion

Back when my 87 GT was new and the national speed limit was 55 mph, I could easily cover 350 miles on a tankfull on the highway. Any more I cover 200-250 miles then stop for gas as my bladder doesn't last much more than 3 hours..

i ran mine till it ran out to see what it would do .from full to empty (car stopped dead ) was 508KM or 304.8 miles .i then put in the 9 litres of gas i had in the trunk and drove to the same gas station i started from and filled it up .total driven was 518KM and total fuel used was 34.35 L .one us gallon =3.78 L so i can barely get 9 gallons in the tank .this worked out to 35.34 mpg , very close to what the duke mentioned above got .this was mixed driving , mostly on 2 lane roads city and country .only about 50 miles on expressways .my car is a 86GT with a turbocharged 2.2L ecotec and F23 5 speed manual transaxle .

quote Originally posted by Old Lar: Back when my 87 GT was new and the national speed limit was 55 mph, I could easily cover 350 miles on a tankfull on the highway. Any more I cover 200-250 miles then stop for gas as my bladder doesn't last much more than 3 hours..

You got 350 out of your v6, let me know the secret....damn I get 220 max on fresh rebuilt 2.8

quote Originally posted by golden dragon: You got 350 out of your v6, let me know the secret....damn I get 220 max on fresh rebuilt 2.8

Depends on the year. If your Fiero is 84-86 the range will be less because of the "smaller" gas tank. 87-88's have "bigger" tanks.

i once did 325 on my 86 se v6 4spd that was solid interstate driving 55 mph.
only put 9.2 gallons back in it... that was all she wrote because it died 50 ft before the pump
coasted to the perfect spot

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1985 gt notchie auto (pic)| 3800 SFI N/A coming soon
1986 se notchie standard 4spd | 5.3 vortec soon

30+mpg on the 2.5L 86 with the 10.3 tank
https://www.fiero.nl/forum/A...030531-2-018929.html

30+mpg on the red 3800 87 with the larger tank.
https://www.fiero.nl/forum/Forum1/HTML/052684.html

[This message has been edited by 30+mpg (edited 02-03-2011).]

The best that I ever got was 363 miles when I had the V6 and the 5 speed. This occurred only once.
On long non stop trips, i usually got 340--350.

I can pull 330 out of a tank. I always get over 300 with a 3.1 3 speed.

most of these v6 results are not consistent with mine .my old setup was a fresh rebuilt 2.8 and 4 speed and i was lucky to get over 200 miles on a tank full .lets hear documented results , not trips down memory lane .car and driver magazine feb 1986 states EPA city19 mpg and hwy 27 mpg for the 2.8 GT 4 speed .everyone who bought a new car back then knows how overly optimistic those figures were .and C/D's observed fuel economy was :
16 MPG . do a test like i did , then get back to us .

i do mostly short/around town driving and get 23 mpg. my last trip from jacksonville to daytona at 70 i went almost 28 mpg.i own a 1987, 2.8 with 37,000 miles on it. not bad for an old car that is just getting broken in. my cruze control works to. the speed limit is 70 in fl. to, i really do enjoy the ride, life is to short. one day i will do the run to the keys.

31. Not 31 miles per gallon, 31 miles per tank 84 4 speed. Car is going to get parted out

my 86 duke 5 speed gets me pretty good kms. i have never check how many mpg it gets but it cost me just over 30 bucks to fill and i get around 400 km a tank i never bleed her dry though always fill up at about 1/4 full.

The 87 Duke 5spd is known to get the best mileage of all the Fiero's, which puts you in a good boat, I have heard many people stating that on long highway runs they can scratch the 40mpg mark.

As to me, the best my 88GT 2.8 gets is highway runs I can usually pull in 32-34mpg. I do several runs from Surrey BC Canada to Aurora Oregon and always get just over 30mpg. However inner city driving, that can drop as low as 20mpg, due to my lead foot, constant drag race starts from every light and having fun. (side note, the motor in my 88 is not totally stock, and has a custom chip designed to run it a tad leaner at cruise and a tad richer at WOT, also has EGR functions disabled in the chip.)

My 87GT 4.9 V8 Getrag 5spd gets nearly identical mileage to my 2.8 however with nearly double the power and fun, just so long as the 02 sensors are working fine. (have had a horrid time with that, when they are giving me problems, the mileage drops to about 9mpg)

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85GT Soon to be 87GT,93 Eldorado 4.9, 5spd Dual O2 Custom Chip, Custom Exhaust. MSD Everything Capt Fiero --- My Over View Cadero Pics Yellow 88GT 5spd Full Poly Suspension, Lowered 1/2" in front, Corner Carver.

I record every fuel up, and I have a documented best of 318.4 miles in my Formula. I remember that trip. It was through lots of construction zones (with low speed limits) but no construction crews, so traffic flowed well. And... there was no ethanol in the gas. Now... I'm lucky to get 220.

My 84 duke with a manual would get just over 300 miles out of a full tank. I'm sure it would have been a little higher if it had been pure highway. My 88 2.8 5spd gets anywhere from 220 to 250 on a full tank.

220 Miles in my stock 86GT 4 Speed. Refill is about 9 gallons, 24MPG. Not too bad for spirited driving. Very rarely do I highway drive, and if I do I'm doing 75 or so, which with the 4 speed, isn't optimal.

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Red 86GT 4 Speed "MrDrift"

My 85 gt 4 speed v6 would at best with mostly highway drivin get 220 on a tank. On average around 195 . The big block fiero gets about 75 miles to a tank.

quote Originally posted by Capt Fiero: The 87 Duke 5spd is known to get the best mileage of all the Fiero's, which puts you in a good boat, I have heard many people stating that on long highway runs they can scratch the 40mpg mark.

Yeah, the mileage I quoted above was based on a mix of city/hwy daily commute driving... If I run out a tank on mostly highway miles, I'll post the results... - kv

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88 GT T-Top 5-spd #338 of 1252
87 SE 4-cyl 5-spd sunroof, spoiler, performance sound
85 2M4 base coupe T-Top 5-spd, rackless decklid, 15-in 88 GT rims, aero-conversion

I won't go any farther than 180 on a tank... just to be on the safe side.

Supposedly stock with a 125 auto
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Notchback GT - I shall call him Judas

[This message has been edited by skuzzbomer (edited 02-05-2011).]

304 highway miles with a 3800SC last September. Still had gas in the tank. After 4t65e-HD changed out for another one, my mileage suffered. Haven't kept up with it but I seem to need gas at the 250 mile mark. I think final drive is higher ratio. Car is an '84.

My '85 duke auto 142,000 miles, engine rebuilt at 117,000 miles, gets roughly 340 (38-40 MPG) miles per tank highway. Getting around 240 in town (29-30 MPG it should better, but the lights are not syncronized going to and from work) usually takes about 8 gal to fill. haven't run her dry yet. Wish I had a good starter in her right now my S10 goes through double the fuel.

I make the Dells run on 1 tank and have just under a 1/4 tank left when I get home 230+miles. I can do Fierorama on 1 tank and am getting down to E when I get home. 310 miles usually around 8 gal to fill

The best I ever did was Dubuque IA to Sioux Falls SD on one tank 397 miles.

I only checked twice when I filled up since I bought the car. This is an 87 GT V6 5 speed with just under 100k stock everything:

1st- 26.8mpg mostly highway with moderate to heavy traffic conditions for most of the time.

2nd- 24mpg same circumstances but more aggressive driving.

I fill it up at 200 because my gas gauge is a liar. =/

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When I bought my 383 Fiero I was getting between 10-13 mpg on the interstate. Granted I wasn't exactly babying it either. I'm not sure on my '85 5 speed duke though as the gas gauge didn't work and I didn't check mileage back then either.

I got 235 out of my tank once in the 88 GT 3.4 DOHC. It was 100% CITY driving, and to date, it is my best record. It was 9 gallons to top it off. 26 MPG.

The key to getting great fuel mileage out of any car is first to ensure it is in excellent mechanical shape and secondly, to drive it with a very light foot. My 88 Coupe, 4 cylinder, 5 speed manual would consistently get high thirties. Did it several times, once exceeding 40 mpg. Tires were 5 lbs over recommended values, A/C had been deleted and I drove it between 55 and 57 mph the entire trip on the interstate. No, I never did allow myself to be a hazard to other traffic. That's the speed the car was designed to travel at. I also never accelerated like an idiot, I was going for mileage, not time. I never intentionally ran to empty.

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Ron

My 86 duke 5 speed, non ac car, had been getting me consistently 36-37 mpg highway, with some around town mixed in there. The best I have ever done is 41 taking it to the shore and back, but I havent been able to replicate that again recently. Gas has gone up to about 15% ethanol around me, and thats killing my mileage, im currently averaging about 32-33. I am commuting to school with this car, it does 120 miles round trip four days a week, from the delaware water gap area in NJ/PA to Mahway NJ, and I check the mileage every fill up. The worst I have ever gotten was 29, and that was a lot of idling around and around town driving, as I had just gotten the car on the road. I have picked up everything from an 87 to convert it to a bigger fuel tank now, give me the extra two or so gallons