so i've been getting 23-25 mpg on my 88 t-bird sport 5.0
think it's about ready to blow up or break down or something lol. curious to see what kind of gas mileage u guys get.
my last tank was 16
8mpg on race gas
5.0 mustang gets about 18 combined
Just the answers the OP wanted to see....
20 years ago when I owned a 87LX tbird 5.0 with 2.73
Its got great mileage. Easy 25mpg....driving moderate.
My next car....87TC 5spees did better....28mpg with more power.
But u can't go wrong with a stock fox 5.0...great setup. Just not terribly fast....stock.
Travis
I believe that transmission, gear ratio, and type of driving greatly effect your mileage.
a.stock 5.0 with 2.73 gears should be capable of 25mpg or more if its running right. the rest is up to you and your driving habits.
ok cool. didn't know they was capable of it. was kinda shocked myself when i done the numbers the last few weeks.was the first time i'd checked the gas mileage. i figured numbers like others posted.
mine is pretty stock except for $8 a peice spark plugs (my brother bought em before i bought the car from him,cant complain on the lifetime warranty though) and a tornado in the air intake.
i drive 50 miles a day to college and back most of it going 60-65,does 1500 rpm on tach at 60 or 65. is that the same for most of u guys?
I get about 19 combined on average, the fuel computer usually reports slightly lower. Honestly though, it's a good thing I don't drive it for the fuel economy.
The Sport does pretty well for me. I haven't really checked the mileage since I removed the TFS-1 cam and installed the H.O cam back into it. It's doing good. I only put gas in it about every 3 weeks. When I get it back from paint I'll do a good test on it and report in.
My old 83 5.0 Cougar got a steady 18 when delivering pizza. That was mixed town, highway, and idling in people's driveways. No AC. My 87 5.0 that I had before did better, but it's been too long to remember how much better ;)
if I got 18 while delivering pizza, then I was doing really good in my old 87 5.0. I rarely hit 45 mph though. lots of stop and go and 25-35mph zones.
my 87 bird sat 1400-1600 rpm @ 65 mph according to the digital dash which only reads 200 rpm increments.
Going from my 2.73 gears to my 3.55's didn't help matters. Not bad, but not as good as with the 2.73's
When I was driving 80 miles a day on I was averaging 25 mpg. 75 mph with the cruise on.
is 2.73's stock i assume?
so mine is in the right range then.was just curious
i wish my cruise worked.I'd prob get better mileage then but also might be easier to fall asleep on them early mornings lol.
When my car was fully stock with 200k miles on it, I would get 20-22mpg average with my commute to school, which was maybe 8 miles. None of that was highway, a lot of lights, but also a lot of cruising (if missing lights) at 30-40mph. I later found that I seemed to do 19-20 city and 32-33 highway at 65mph and 30 at 75mph. Years later with electric fan and slightly better flowing HO upper intake, I saw a 1-1.5mpg increase overall, and managed to eke out 34.5mpg highway at 60-65mph (I tested this a few times back to back to account for atmospheric variables). I saw no noticeable impact when I went to a '93 Cobra based motor (heads, intake, new exhaust) with 8.9:1 compression. I would use 4.1-4.2 gallons of fuel each way on a 140 mile trip I was making every weekend between Vancouver, WA and Federal Way, WA (tripminder and quarterhorse logging matched up very close). The lowest trips were 4.5-4.6 gallons with traffic/rain/winter. I also saw no change when going to GT40P heads. My highway at 65mph dropped to 26-27 after going to 3.55's. 3.08's get me 30-31mpg. No improvement in city economy.
Now that I live in the western Portland, Oregon area, it is about 160 miles and 5-5.2 gallons of gas. This was last with GT40P heads and 3.08 rear gears, using a 4R70W transmission (0.7 ratio 4th gear).
I don't care much anymore - I want to stick the 3.55's back in. My 80mpg daily driver is the one responsible for fuel savings.
And now you know ;)
My Thunderbird with the mods below, 3.73 gears, and a non-lockup torque converter gets 14 city and around 22-23 highways at a steady 70 mph cruise. Highway cruise speed is about 2800rpm at 70 mph. I could maybe get a mile or two more per gallon if I drove it like I do my DD Focus but I tend to, ahem, use the power. That results in poorer fuel economy. I didn't set up the car to get good gas mileage but instead be fun to drive.
Yep, but most of it is in the gears. With the economy drop from 2.73's to 3.55's, and the fact that the tires would permanently break loose/drift sideways on the 1-2 shift at WOT in the middle of summer when using 3.55's, 3.08 seemed like a decent compromise, and got the highway back up over 30. I've missed the extra torque multiplication though - dry weather only breaks traction on the 1-2 for a second now. 3.55's were quite a bit more fun, but performance wise, the 3.08's provided more daily drive-ability in economy, safety, and more torque multiplication at "passing speeds". 3.55 has to shift right below the speeds where you normally find yourself stuck behind a slow driver, when using the 4R70W's ratios.
With the right combination, anything is feasible. It's easier to just throw on big parts and enjoy the incremental performance increases.
Stock, 18 city, 32 highway is probably the max one can expect, with an average of 20-22mpg. Expect 14-16mpg if you average 15mph in stop and go traffic - that's where the v8 really gets you.
These gear ratios are so low (or high I should say) compared to what I'm used to hearing when I had my Rangers, we had 3.45 3.73 and the 4.10.
My last one was a '96 2.3 manual 2wd with 3.45, I got 25 mixed EASY, but it couldn't get out of it's own way. The one before that was a '03 3.0 Auto, also 2wd, with 3.73, that thing was slow as well, and drank as much gas as a CFI 5.0.
im not buying it for a minute anyone here gets 30 to 35mpg in these cars be it a 4, 6 or 8 cylinder unless your going down hill both ways.
I get 22 in my appalachian mountain highway / byway roads
I get a hard steady 25 mpg in flat land states.
typically i get 19 city.
i even have a 2.73 gear
how much do you use cruise control? that actually eats up quite a bit.
I use it all the time when it works.. but its been broke twice and with thousands of miles with and without cruise.
im up to 260k now
seek,
i worded all that wrong above,, i should have said what i said differently and sorry for how i typed it out.
your a very tech savvy guy and what i should have said was "how in the hell are you doing that"?
maybe the quarter horse engine managment system you have?
do 55-60mph max on the freeway. ill bet you see 2-3 mpg right there.
until a few years ago, we had a state wide speed limit of 65. since they bumped it up to 75 and even 80mph in the middle of no where, I've lost quite a.bit when driving those speeds.
I got 30 mpg in my 87 LS with V6 all the time on trips between Maryland and Mississippi and Maryland to Florida. I also got 29.5mpg all the time on those same trips in my 96 MarkVIII. Speeds were not slow. The sage green 85 wasn't anywhere close to that and it also had a V6. My V8 Cougars aren't anywhere close to that either. They are 24, 25 max with similar driving.
No worries.
I've had a lot of variables over the years. With the stock motor, I was using 35psi and I do not remember if it was using cheaper/harder tires at the time. All of my highway testing was done filling up right before getting on the highway, and engine already warm. Longest calculated highway trip I've made is 310 miles, which matched numbers I was seeing on the weekly 140 mile trips (each way). While I did add a quarterhorse somewhere along the line, it wouldn't affect closed loop, where I kept the vehicle. What I do recall:
Completely stock, I didn't know that much about cars, newer driver, etc -30-ish mpg at who knows what speeds.
SO with HO intake, 35psi tires, 2.73 - 32-33mpg at 65mph
SO with HO intake, 35psi tires, 2.73 - 30mpg at 75mph
SO with HO intake, electric fan, 35psi tires, 2.73 - 34-35mpg at 60 or 65mph (do not remember the exact speed on this morning - I was shooting for consistency between mechanical/electric fan tests rather than other comparisons)
The start of engine work, building for efficiency, and trying to get the most out of the vehicle (including more even tire tread wear) - tire PSI did not seem to change much in economy with softer unidirectional tires, but it was higher:
GT40 engine with HO cam, electric fan, 45psi tires, 2.73 - 34mpg at 65mph
GT40P engine with HO cam, electric fan, 45psi tires, 2.73 - 34mpg at 65mph
GT40P engine with HO cam, electric fan, 45psi tires, 3.55 - 26.5mpg at 65mph
GT40P engine with HO cam, electric fan, 45psi tires, 3.55 - 24mpg at 75mph
GT40P engine with HO cam, electric fan, 45psi tires, 3.08 - 31mpg at 65mph (consistently)
GT40P engine with HO cam, electric fan, 45psi tires, 3.08 - 34mpg at 70mph pulse, 55mpg decel fuel cutout glide on a different highway, commute to work
TF 170/ported GT40 intake engine with HO cam, electric fan, 45psi tires, 3.08 - no clue. Haven't driven it enough.
On that note, I'd like to try improving drag resistance as a learning experience. With what I have learned about my Insight, I could probably improve back up to/over 35mpg with enough under body modifications. I don't know if I want to try leaner fuel mixtures with the aluminum heads.
And for comparison:
2000 Honda Insight 5 speed - 75mpg at 75mpg (22:1 AFR 50% of the time)
2000 Honda Insight 5 speed - 86mpg at 65mpg (22:1 AFR)
With a V8, the big difference comes at idle or low speed - there are much higher losses in city driving with a v8, than with a v6 or i4. Highway speeds, rolling and wind resistance impact things more. This is only true to an extent though, as obviously going to higher numeric gearing/higher rpms obviously hurts economy greatly also.
These are all "maximum" numbers, with simply using cruise control and never dropping out of closed loop. The numbers also varied between winter and summer. The Tbird numbers are still nice considering we've had E10 fuel for some time. I'm not comfortable enough trying to tune the vehicle to run on E10 better, because of all the timing issues that could arise.
My old 88 XR-7 used to get in the mid 30's on the highway. Towards the end, it was the best part of her.