After I posted here (http://www.foxtbirdcougarforums.com/showthread.php?t=14075) about the '84's incredible gas mileage, I noticed a lot of people adding their fuel economy figures. Thought it might be a good thing to start a new thread in a place where more people might see it. Feel free to post your fuel economy here (engine, regular or premium fuel, highway speed, etc.). Maybe we can even start a Top 10 list, by engine...? We know that the 2.3 guys usually enjoy regular decent fuel economy, but some V6 and V8 people might challenge that.
Anyhow...with gas at around $3/gallon in the U.S., it's kind of important to know what we can get out of these older cars. Some of them might just surprise you. :)
My '96 4.6 gets 26 mpg on the interstate at an average of 72 mph, but I've witnessed returns of 28-30 mpg in ideal conditions.
I have no idea what the '86 averages due to the way I drive it. It seems as if 50% of the time I've got the throttle wide-open, and the car rarely sees interstate travel.
My best fuel mileage figure with the HO so far is 28mpg on regular gas, and in a mix of city and highway driving. On average, I get 22-24mpg.
88 5.0 Regular gas
Down and dirty, stall and crawl, worst case city 12-14
Average 19-22
All highway 30
My trip to and back from carlisle avg. at 90 mph was 20.5
93 octane.It was mostly all highway.
84 5.0 (needs tuned)
In town when driving nice-12
Highway-75mph-22
Highway - Bad
City - Badder
im still waiting to burn a tank of gas since the exhaust and pulleys. i got about 18 mpg before, at about 250 miles to the tank(not completely empty of course). but already ive gone 150 and burn ed between 1/2 and a 1/4 tank. im guessin gim getting about 21 mpg now (still not excact figures tho) but thats not back considering i drive like a lunatic. :evilgrin: :dunce:
90 Crown vic, 324-xxx miles, between 17-18 MPG all city driving.
84 Fila - God only knows
Tripminder usually averages right around 27.0. I reset it every time I get gas. Its usually the average of 150-200 miles.
I can get a good 34mpg or more on a nice straight road doing 55mph. Or 28-30ish on an interstate doing 70-75.
I used to think 20ish around town but I think its closer to 25.
i havnt reset my fuel econ avg guage in a very long time. i'ts driven to north carollina and back to ga 8 times, when i was going to and from school (hellish traffic) and then down here with a slipping transmission i still average 21.9-22.3mpg at an average around 45-50mph (havnt reset the avg speed since the economy either. and i go through back roads 80% of the time running 60-65-70-75mph. btw, non catted y piped SO with smog pump still on and even a non working ac compressor. and i dont run anything but 87, specially when 87 is ****in 3.50 a gallon (and since i have a digital read out of litters and gallons, the pumps are ripping you off. i have a 22 gallon tank. i stop to fill up and got 7 gallons in the tank. but some how i pump in 19 gallons of gas. wheres the 4 gallon reserve tank on these tbirds?)
The absolute best I ever did was a 40 mile trip on a hilly back road. I had just installed the tripminder and was trying to see just how good I could do. The temp was about 70 degrees, I drove at no more than the 55MPH speed limit except when coasting down hills, and when I was going up hills I only gave it enough pedal to keep moving - I actually slowed down quite a bit on the uphills.
This was in my '88 T-Bird, 5.0 V8, the only mod being catless 2.25" true dual exhaust with stock manifiolds, 2.73 rear gears, and the A/C running.
The result: 34.8 MPG, as indicated by the tripminder. I've never actually figured it out by filling the car, driving it a certain distance, then filling it again - that would be the only accurate way of measuring, but I'll have to go by the tripminder.
Normal driving I got 28-30 highway, 12-15 city. Don't know how the 3.55 gears will affect that because I haven't actually driven it yet - I suspect city will go up, highway will go down.
The sickening thing is that I only get about 25MPG highway with the Volvo with its bitty little 5-cyl turbo, and city is about the same as the Bird's 12-15. Hard to believe a 1988 V8-powered domestic car gets better mileage than a 2000 5-cyl powered European car...
I would guarantee the pump is a lot more accurate than the gauge in your car. The "4-gallon reserve tank" is the amount of gas between when the gauge indicates full and when it actually is (and if your gauge is working correctly, there will be a further "reserve" between when the gauge indicates empty and when the car actually stops). When I had the disco-dash equipped '87 Sport I'd fill the car before visiting family in Yarmouth (200 miles away) and drive about 90-100 miles before the gauge indicated that I'd used any fuel at all. Once it started going down, though, it would do so quickly.
The only time I ever checked my mileage was the summer of 1988. My neighbor had a 1987 Thunderbird with a 3.8 and he kept bragging to me how he was getting 28 mpg with it on the highway.
I had planned a trip to visit my sister in Boston so I decided it would be a good chance to check my mileage.
On the trip I filled up near Buffalo, NY and heading East through NY state, with three people in the car and the air running I got 32 mpg. This was when the car was completely stock.
Needless to say, I was sure to tell my neighbor about it when I got home. ;)
Brent
:cougarsmily:
That's a cool story, Brent.
88 tbird: alcohol fed 434cid 8 gallons to the mile.
ok, ok, it get's 0 now, but did get 28 mpg highway w/3.08 gears, aod, 3.8cid.
The 5.0 5-Speed Sport averages about 23 mpg regualr daily driving for me (moderate beating on it avg speed prob. 55, lots of country driving)
The 79 ranchero 5.0 same daily driving as above gets 16 mpg and on my last highway trip with an avg. spd of about 70 I got 20 mpg and it needs to be tuned. Not bad for a 28 year old carbed 3 speed.
23-25 mpg 90% city 10% hiway
Original SO 5.0 in the '88 with 175,000 miles, the best I got was 24 mpg highway/ 22 mixed - regular 87 gas
HO 5.0 stock - 23 mpg highway with a blown head gasket ;) (few years ago) - 93 premium
HO 5.0 after all mods - 18 mpg mixed running around in Drive not OD - 93 premium
My 93 5.0 HO got 32 MPG on my first trip to Cat Jam in 2004. Cruise set to 65, didn't touch a pedal for almost 200 miles.
Right now, gets 20 mpg highway, 13 local. I think I have a wiring issue, the car is running extremely rich (to the point where it fails emissions due to hydrocarbons), but it has no other issues, and will not throw a check engine light.
I seem to get about 22-23 city...
I was getting 26 highway (running the car at about 78 mph), I had wanted to see if it improved after I changed to royal purple and did some other stuff when I drove out to Indianapolis (and I kept it around 70 the whole way out). However, gas was so god expensive when I got out there ($3.50+ for 93) I just put in enough to last me the weekend and get me back to Ohio where prices were more reasonable.
However, I did make it from my apartment to my hotel just north of Indy on about 3/4 tank of gas (400 miles). I wish I coulda filled it out there to see if my mileage did improve, but oh well.
I do usually get around 320 miles to 3/4 tank of gas on mostly city driving (and it usually seems to need 14-15 gallons to fill it from 1/4 tank)
I'm wondering how many of you guys have to drive up and down a bunch of hills to go basically anywhere? I do, and I know that negatively affects mileage.
Also, I still wonder how any of you TC guys get 28-30 mpg on the highway, mine didn't even do that when it was stock except for a cone filter on the VAM.
1988 Cougar XR7
18 in the city and 20-22 on the interstate at 80mph turning 2000 rpm
1996 Thunderbird 4.6
20 in the city and 22-24 on the interstate at 80mph turning 2500 rpm
Thanks, he tried for probably two years to beat my 32mpg, but he said he could never get more than 30mpg out of his.
I guess he needs to take a driving lesson from Eric. ;)
The best part of telling him my results was that I wasn't even trying, I was just driving normally. Of course it was all highway miles but I did run into some quite hilly areas and the turbo was on boost sometimes to maintain the cruising speed.
He never got over it, and when I see him occasionally I still bring it up. :evilgrin:
In his defense, he's not not a car guy, so he never grasped that my car was running in economy "Pinto" mode 95% of the time. He just knew it had a turbocharged engine and it was the "hot rod" version of the Cougar so his Thunderbird should be getting better mileage.
Brent
:cougarsmily:
City 14-16 mpg
Highway 22-24 mpg.
That's with a 10:1 compression small block with 12* advance and 93 octane :hick: ..............And if I keep my foot out of it
Car 1
15-18 mpg
Car 2
9.8 - 18 mpg
Note those are only trucks...
When the cougar Ran, it was like 14 at city and 18 at higway....at 55. I never got that carb running properly. At the end i liked the huge clouds of black smoke when acceleraing...
In my mark VII I get about 21-26 mpg my expedition on the other hand is anywhere between 9-14 depending on if im driving ir or my wife,
340ish hp 10.5/1 4.6 DOHC best avg 31.3 mpg.
typically get 25-27 mixed driving. highway, cruising and a holeshot here and there.
worst ive done was 16-17ish driving like an ahole.
prem 93 or better only cause of the tune and compression...
daily driver jeep cherokee....typically 17 mpg
don know about that, my guage doesnt say F for any longer than it takes to get to 17 gallons. i mean when it says E it doesnt go 50 miles extra or anything, it usually means gas NOW.
Katrina: 12-14 driving around town. Modded HO, 5 speed, 3.55's.
Rita: 17-19 around town. Stock HO, AOD w/2000 stall non-lock, 3.55's
I dont want to know.
i would guess 17-18 city when i drive like a normal person/ an a dash of old lady.
on pay day 14ish driving like an ass
highway im not sure im not on it long enough to go though a gallon
'85 Mercury Cougar
[/I]
[INDENT]
- [/INDENT]City: 14-18 mpg
'87 Ford Thunderbird
[/I]
- 3.27 gears
- AOD
[INDENT]- [/INDENT]City: 17-21 mpg
- Highway: 24-28 mpg[/B]
I drive like a granny, and go ~70 mph on the interstate.
As an buttstuffyst, my opinion is a "Top 10" mpg would be baseless. There are far too many variables to be accounted for.
Eric, keep us informed of what kind of mpg the car gets once you use a larger amount of gas per fillup (15-18 gal).
20-22 all city/rush hour, 24-27 average, 30 highway at "75mph", 33mpg at "65mph". Actual speeds are a little higher as my speedometer/tripminder reads low with these tires. Typically do round trips to Federal Way, WA (145 miles each way) on 9.5 gallons of gas which is a mix of anywhere of 60mph to 80mph.
and of course, 8-13mpg climbing hills, 130mpg going back down them. 2mpg at WOT.
Standard 5.0 SO, 213k mi, but with HO intake parts. Still fails emissions though, even with every smog system working great (its all a year old now though, along with all vacuum lines). Next year I may have to stick some of that "emissions fuel treatment" in there before I run through so I don't have to deal with getting another waiver from a repair shop on their list (all overpriced).
I got around 26 on the freeway with my old 86 5.0 aod.
both 87 3.8 aod cougars got about 450 miles to a tank... I cant seem to remember how big the tanks were though. And I usually used all but the last gallon.
85 XR-7 32 hiway ,avg 24
91 SC 5 speed 27 hiway,avg 20 (heavy foot)
95 XR-7 4.6 28 hiway,avg 20
then i just have my trucks 76 F250 4x4 460 14 hiway and avg 8,78 bronco 351M with 35's 10 hiway 7 avg they don't see much driving lately
So far it seems like most people with these cars are still getting fuel economy within the EPA estimates from when they were new (and not the new revised versions). Cool. Keep 'em coming!
Just an update...I finally filled up the '84 after the trip...160 miles, 7.4 gallons = 21.62 mpg.
So for the trip, 480 miles and 17.2 gallons = 27.9 mpg.
22-24 city MPG with foot in it doing 0-50 off every light because theres nothing better than smoking imports and knowing you get the saem or better gas milage.
high way 30 or better depends on driving speed and traffic
Is that a bit exaggerated? I would hope for such mileage once I get a new motor (and HO), but I don't see a HO, even stock, getting 30mpg on the highway with 3.73's. The most accurate way I can get readings for these cars is to count the actual miles manually (tires, gears/gearing, etc can give you numbers that are far from reality), then divide by the gallons used shown by the tripminder (since fillups to "full" vary). I just can't see a HO, even with 2.73's, getting 30mpg at anything above 45mph (where the old highway numbers were ran at).
If I'm wrong, great. It means I can get more power and a new/quiet rearend with the exact same economy as the stock SO (with electric fan, tuned great, ...). Just curious, thats all.
finnally ran a few tanks through the cougar
:D
23ish in town 28-32ish freeway
average shown below
I've gotten 26.2 on a trip to Carlisle and 22 running around up there which included a couple trips to Harrisburg... The trip was mostly 60-65 mph and and I have 3.73s... Never check it around here, as I put just enough gas in it to race before I head for the track...
Eclipse 22/25 City 25/32 Hwy
Cougar Used to be 16/18 City 30 Hwy
Now who knows? If I run off two barrels it will probably be better due to a less restrictive engine. If I run it hard I would expect 10/12 City 16 Hwy
I average 17-18 MPG in mixed highway & backroad driving.
I get about 21 MPG in steady highway driving @ 65 - 70 MPH
I have the injector's dialed in properly with the TwEECer so my Tripminder is fairly accurate now (+/- 2MPG), though I generally found it to be excessively optimistic in stock configuration, so don't mind me if I take those numbers with a grain of salt.
I read a post where someone claimed to see a significant mileage improvement by using the "decel fuel shut off" feature in the ECU, so perhaps I can improve my mileage somewhat by doing that. I may also adjust it so that I am running slightly leaner than stoich at light-load cruising.
i'm having issues with the engine stumbling when i gas on it, so i bumped the timing to 14 deg and use 93 octane.... i drive a mix of stop and go and ingterstate.... i average 20.3-20.6 according to my tripminder, but the pump says i'm closer to 19 mpg
How much so, percentage wise?
In my experience, the tripminder is dead on with fuel usage, the miles then depend on how accurate your speedometer is (no speedometer is 100% accurate, but you can get close with the right tires/parts). When I put on snowflakes, I meant to get the cheaper and same size radius as my old 14's - 225/55R-16 but accidently bought factory 225/60R-16's so now I get 62-63mph speeds at 60mph readings than what I manually calculate it. Haven't touched the speedometer gear as I want the cheaper and more widely available 55's next time I need tires.
Anyone know how accurate these were on the factory cars they came on, in stock form?
You can post-process a TweecerRT log to find predicted mpg gains. I believe the "Decel fuel shutoff" is active when the engine is warm, the TPS is closed, and the rpms are above 1200.
If you filter out injector PWs to 0 when these conditions are all true, sum them, and compare the total PW to your non-filtered results, you can find a percent different. You can also find total distance traveled to get an actual mpg number.
You can go through the same process to find the improvement by changing the HEGO bias.
I see we have another TwEECer junkie here :D I will likely just implement the decel fuel shutoff & see what, if any, effect it has on drivability. Hopefully I will see measurable gains in my mileage. I suppose I could dig up an old log and try to filter it somehow to get an idea of the theoretical gain. HEGO bias changes would be difficult to predict due to interpolation between cells & possible offsets/OL operation if the loop has trouble compensating (I've seen this already).