1987 Ford F250 - 25mpg hwy or bust

[Miller88]

As long as it's a load range E tire, you will sacrifice no load carrying capability by going to a 215 85R16 tire, for example. That may give you a slight increase in fuel economy.

What about doing the PS pump on an AC clutch? Turn it off when you don't need it?

Being a 3/4 ton, it probably has a TTB front suspension right? If it has the beam axle, that would make it easy to do a belly pan. Even if not, you should be able to make one that bolts to the frame for most of the truck.

[Piotrsko]

OK, I'm a newbie here, BUT: got a 2000 f250 6 speed & 3.73 rear end that I claim @ 20+ mpg city for 135000 miles. Back before fuel reformulation i got 25 mpg stock summer. Not a lot of differences between the 250 and 350. In this case, axle spacers and door stickers. Yes I have the turbo and intercooler, but don't run a lot of boost.

stuff I did: cab top campershell with BOOT not windows. played with raising and lowering. raising it cost me 5% for every inch up, lowering it did approx the same for increases. I suggest using the 250 rear axle spacers which lowers the rear about 2" at a mild load capacity loss which can be avoided with helper springs\airbags. NEVER go above 2000 rpm, try to stay at 1750 which is theoretical best efficiency if you can trust Ford owner's documents. I run really lean because of a fuel pump issue (about -28 on LTFT)

Heavy it responds best with hypermile techniques because all that mass doesn't want to stop. I just whine a lot starting off and while going up hills.

YMWV

[6 Speed]

Originally Posted by Miller88

As long as it's a load range E tire, you will sacrifice no load carrying capability by going to a 215 85R16 tire, for example. That may give you a slight increase in fuel economy.

What about doing the PS pump on an AC clutch? Turn it off when you don't need it?

Being a 3/4 ton, it probably has a TTB front suspension right? If it has the beam axle, that would make it easy to do a belly pan. Even if not, you should be able to make one that bolts to the frame for most of the truck.

I plan to go to hydroboost, disconnecting the steering would be a bad idea. As for the tires, the 215 will be shorter than the 235, which would correct my speedometer, but throw my odometer. Oddly enough, one is spot on, one is fast lol. The narrower profile would help the aero, but it might not be noticed with the belly pan and the massive airdam I plan to install.

Originally Posted by Piotrsko

OK, I'm a newbie here, BUT: got a 2000 f250 6 speed & 3.73 rear end that I claim @ 20+ mpg city for 135000 miles. Back before fuel reformulation i got 25 mpg stock summer. Not a lot of differences between the 250 and 350. In this case, axle spacers and door stickers. Yes I have the turbo and intercooler, but don't run a lot of boost.

stuff I did: cab top campershell with BOOT not windows. played with raising and lowering. raising it cost me 5% for every inch up, lowering it did approx the same for increases. I suggest using the 250 rear axle spacers which lowers the rear about 2" at a mild load capacity loss which can be avoided with helper springs\airbags. NEVER go above 2000 rpm, try to stay at 1750 which is theoretical best efficiency if you can trust Ford owner's documents. I run really lean because of a fuel pump issue (about -28 on LTFT)

Heavy it responds best with hypermile techniques because all that mass doesn't want to stop. I just whine a lot starting off and while going up hills.

YMWV

2000 will be the Powerstroke, which I understand was more efficient to begin with. I totally hear you on the fuel though. I've noticed how the gas formulations have changed over the years and the effects they've had.

A camper shell is out of the question for me, the stock bed is coming off in favor of a flatbed with cabinets. I do have a collapsible kammback planned for highway trips though.

Any lowering I do on the rear of my truck is gonna have to happen by way of longer shackles and/or hanger flips. My truck doesn't have the spacers and tall perches like some others do, the leaves on mine sit directly on the axle pad. I do want the truck lower, and I'll go as low as I can without flipping the axle. I'll have to get the dream beams for the front and some shorter coils as well. I don't see going much lower than 3 inches though. It's a 3/4 ton not a half ton lol.

I try to keep the revs fairly low, but the new exhaust is just lovely to listen to...I can't help the urge to play around some lol.

[Christ]

Originally Posted by Piotrsko

OK, I'm a newbie here, BUT: got a 2000 f250 6 speed & 3.73 rear end that I claim @ 20+ mpg city for 135000 miles. Back before fuel reformulation i got 25 mpg stock summer. Not a lot of differences between the 250 and 350. In this case, axle spacers and door stickers. Yes I have the turbo and intercooler, but don't run a lot of boost.

stuff I did: cab top campershell with BOOT not windows. played with raising and lowering. raising it cost me 5% for every inch up, lowering it did approx the same for increases. I suggest using the 250 rear axle spacers which lowers the rear about 2" at a mild load capacity loss which can be avoided with helper springs\airbags. NEVER go above 2000 rpm, try to stay at 1750 which is theoretical best efficiency if you can trust Ford owner's documents. I run really lean because of a fuel pump issue (about -28 on LTFT)

Heavy it responds best with hypermile techniques because all that mass doesn't want to stop. I just whine a lot starting off and while going up hills.

YMWV

You also have a completely different engine that's direct injection and turbocharged... it's more efficient right out of the box.