Ford428CJ
FE Freak!
I run 315/75/16s with 4.10 gears and a c6 and get 14-16 or so. Thats with no Moose Pump 
and turned the screw all the way in.
and turned the screw all the way in.
Moose Pump Unloaded MPG
- Thread starter icanfixall
- Start date
LCAM-01XA
Full Access Member
JD, can you go and measure how wide those tires of yours are at the tread? I got 235/85-16s now, and to say I got a tendency to sink in soft terrain would be an understatement - I was thinking of the 265/75-16s as they would be wider, but the overall tire diameter would be the same as what I got now.
FordGuy100
Registered User
265/75/16 should be around 10.5-11" in width.
I might swap to 255/85/16's, a little skinnier than the 265's, but taller.
Diesel JD
Full Access Member
Can't measure right now. Its at my mechanic's house. They're 31" tall that I know for sure. Mine had 235s when I got it, and I hear that's what they came with from the factory. Maybe I should add some of those when I get around to new tires. At least I couldn't get the Mud Dawgs I wanted...they would have been less fuel friendly, but in those days diesel was about $2.15 a gallon and I could brew up a batch of bio for 75-90 cents a gallon. Good ole days.
LCAM-01XA
Full Access Member
So those tires will work out nice for me - they'd be going in the front only anyways. Also, the stock tires for my truck actually are 215/85-16, but I've never really seen a diesel truck with those, ever.
Darrin Tosh
IDI Hound
In Dodge's probably. Don't know what they weigh, but they LOOK lighter.
There are guys getting 20 plus usually 2wd reg cabs with 5 speeds with no modificatons, and stock tires. I am real happy with the 17.5 that I got so far. I think my truck is right at 8K pounds and yes the big tires do hurt the mileage.
Diesel JD
Full Access Member
That sounds like my friend's 2 Cummins, 5 speed reg cab littlle to no mods. I doubt if they are any lighter than say an F250 XL reg cab with a T19 or ZF5, which also could get high 10s or low 20s mpg under the right conditions, but I think the Cummins is almost always a tad bit more efficient.
