Tell me what ya'll think...

[marvin2]

I am looking at a 72 f250, 4x4, hi boy, w/ 390 and auto trans. The owner says he believes its geared with 4.57's.

I will be needing to drive this just primarily around town (west texas)...I would assume 15 - 20 min trip to work each way...and then just here and there around town. Any guesses at what I would see for mpg? Also, how painful would it be driving this truck around with it geared so steep?...meaning would 50 mph seem like the thing is gonna blow up....would it even be capable of anything over 50? Thanks guys!

[mljjones67]

I would guess 5 to 10 mpg.

[fireguywtc]

4.57 would be awfuly low geared for a daily drive imo. you could do 50 but it would be wound pretty tight. I would also guess with the driving style you listed and the gear ration you wouldn't see over 8 mpg very much. If you like it and want to buy it I would raise the ration to 3.73, would make it a better daily driver.

[marvin2]

Any idea what a gear shop might charge to swap out the gears to a 3.73...including the gears?

[fordman]

i dotn know. but you will have to change both the frotn and back gear so they match. or they might over run each other.

[marvin2]

Sounds like a lot of work. I love this truck, but I think I might need to pass on it. I don't mind getting crummy mpg, but 5-10 just won't work for my daily driver.

[fomocoguy]

Well it's hard to say what highway speeds would be like without knowing what size tires it has. If it's running 35's or 38's it would probably be fine. My truck has factory 4.10's and 33's and it will do 70 all day. That being said, my truck never gets better than about 8 mpg. My speedo is off by about 5 mph at 60 so that may be affecting my calculations a bit. Anyways the point is highboys get crap mileage no matter what.

[speed bump]

I would place a bet that it has 4.10s in it but you can check by taking off a wheel and unhooking the driveshaft and counting how many turns the pinion makes for one turn of a wheel.

Personally with a 1500lb welder and a manual with a 360 I get between 7.5-9mpg in my truck in around town driving.