I have a 1976 F250 highboy with 35 BFG A/t and 4.10 gears from the factory, When im going about 75 down the highway its at about 3500 RPMs. Is there a better gear ration i can run to cut that down and get better gas mileage?

 

You may not like my answer very much but the easiest thing is to slow down. New gears are gonna cost you some bucks. 60 is usually as fast as I go...I don't have to get on any major highways to get anywhere here.

 

I have the same combo and turn about 3000 rpms @75mph.

Are you taking into consideration the 35's throw your speedo off?

If your speedo reads 75mph you're actually doing closer to 87mph which would put you up near 3500 rpms.

 

Throw on some 37s

 

My 73 wears 35s and 3.50 rear gears. That's the lowest gear I would recommend for a 4x4 with a 1:1 top gear ratio.

 

LOl... my 2WD 78 long box has 3.50 gears and 31" tires and I'm always looking for that elusive 5th gear going down the highway! I get 15 mpg at 50-55 mph... so its a good thing that it isn't my only daily driver. My long time Toyota gets 40+ mpg but the truck is much more fun as ya know!

 

That's what I said haha

 

Dude, my 2004 F150 4WD only gets 15 mpg (@ 60 mph), so I think that's pretty good for a 34 year old truck!

 

I was just driving my truck today, 50mph is 3000rpms...

 

Using the speedometer or a GPS?

 

Using the speedometer or a GPS?

 

using a GPS

 

3000 rpm at 50 mph? Must have gears lower than 4.10 or a worn out torque converter.

 

I took mine on the freeway for the first time this weekend and hit 57mph according to the GPS. It felt wound out and I wasn't willing to take it any faster.