1991 F-250 2WD 4.9L I6 MPG estimates

[Frank Lee]

F150. Yep, that's the one that kicks down if a bug hits the windshield (slightly better now that my new tires are only one notch oversize instead of two). I'll cruise it at 50 mph for long distances too. ANY SPEED over 55 is very atypical for me in this truck. Guess I need to find an '85 to trade my '94 sow in on.

I wasn't thinking of the diesel Rabbit's EPA when I said 60mpg- I was thinking of the times I've seen them get 60 mpg.

[roflwaffle]

If you're serious, make sure it's a 49 state'er w/ the feedback fuel system, which is pretty much a Carb w/ something controlling the mixture. The 49 state 4spd carb'ed toyota pickup of the same year pulled 40mpg@50mph, so naturally I'm thinking about grabbing one of those if I ever see one cuz my CA-spec FFS 4spd sucks, although it's mpg issues are exacerbated by running w/o a thermostat and never warming up.

[Frank Lee]

I'm not serious. I don't believe for one second that the '85s got 70% better fe than the later ones.

[Big Dave]

Maybe its time for Isaac to respond. We can yap all day but it is his truck and he's the one who has to make it happen.

[roflwaffle]

Originally Posted by Frank Lee

I'm not serious. I don't believe for one second that the '85s got 70% better fe than the later ones.

In that case it's a good thing no one mentioned the 85's (F series) getting 70% better mileage than the later models. That would be, what, mid/high thirties? Anyhoo, like Dave said, it's up to Isaac. Whether or not they go big bucks, start smaller and try to get up into the mid/high twenties, or do anything at all, is up to them.

[Frank Lee]

17-18 x 1.7 = 28.9-30.6

[roflwaffle]

Your truck doesn't get 17-18mpg on the actual highway test, more like ~22-23mpg IIRC. An I6 that pulls ~28-30mpg would get ~1.3-1.4 times the mileage. As was mentioned, even if your truck is rated at ~22-23mpg, you tend to see ~18mpg, so realistically we're probably looking at ~23-24mpg w/ the same conditions, maybe ~25mpg since someone w/ a MT can keep it in 4th where the auto would drop a gear, at a ~50mph cruise w/ a stock 85'er rated at ~28-30mpg, maybe better too, who knows. Aeromods and taller gearing may be able to push that up, and they're pretty cheap to do, at least temporarily in order to see if they work. Ford clearly had more efficient setups than your 302/auto, and the tests show that, even if you don't believe it. I think the OP should start w/ the cheap/easy stuff first, and see where that gets 'em. If they aren't satisfied, then they can go w/ the big buck mods.

[Frank Lee]

Go to fueleconomy.gov; type in 1994 Ford F150 4x4 8cyl a/t 4-speed, and you will see:

12 city/14 combined/17 highway for the "new" ratings and 14/15/18 "old", hence the "17-18" I used. And, that's what it delivers even with semi-hypermiling.

The only F150s that pull 28-30 are falling down into the Grand Canyon at the time.

BTW, the 302 equipped truck has an IDENTICAL to the I6 highway rating of 17.

[roflwaffle]

Mixing and matching different EPA ratings is where you're getting off track. If you're using the 1984-2008 adjusted ratings, then compare the "old mpg", as it appears on the fueleconomy.gov site, for your F150 at 18mpg highway, to the "old mpg" of a 85 MT I6 F150 at 24mpg highway. I'm comparing the unadjusted ratings (download and unzip the stuff on the EPA site for those), which is the test result the EPA gets before adjusting it for more aggressive driving, and those are 23mpg for your truck and 30mpg for the 85. Either way, we're looking at a ~30+% difference in highway mileage.

[Frank Lee]

Ya can't get much less aggressive than my driving. 23/30 No way! I ain't gonna believe it til I see it.

Dave and that orange diesel are doing well and they aren't even up there, and they have mods and that 30% diesel advantage too.