D0T-C0M

I did a 100mi trip and averaged 16mpg with 305/65R18 BFG K02 tires with my 5.0L. It works out to about a 33.6" tire. I was driving 65-70mph most of the way so I could have squeezed another 1mpg out of her I think if I had driven 50-55mph. Its very surprising to hear that the 3.5L isn't getting better numbers than my 5.0L . Your tires must be pretty aggressive. Make sure to air up as much as you can to reduce the rolling resistance. Your gearing isn't helping either.

GregSBF

Unless you're having a real problem getting moving in first gear just run in 5th on the highway. That's what I do with my 33s. I have 3.31 so 6th at 70mph is just over 1500 and kinda lacking into a strong head wind. Drop to 5th and it's still only about 1900 which is fine.
Changing gears on a 4x4 is not cheap. You can buy a lot of gas for the 1 or so mpg you'll gain back.
If you do change don't just go to 3.73 though. That's only 0.18 revolutions. For the cost go to 4.10.

Chris70

If you're really concerned with the mpg your best bet would be dropping down to a lighter shorter tire. Maybe 33's

Incorrigible

I'm in the lower 13's/heavy foot and lower 14's/light foot both tests over a week+. 50/50 hwy/town driving. I definitely see more turbo boost to maintain at least 75mph speedo (gps 80mph) on the highway. At 80+ speedo (85 gps) in seeing the boost gauge at 30% or more on anything with a slight up grade.


I Haven't fixed speedo yet and was high 16's before wheel/tire swap.


How'd you calibrate the speedo FX4?

Chris70

He quoted mixed driving was in that 14.1-14.7 range not highway at 65-70mph

GregSBF

3.73 would move you from 1700 to 1800rpm at 70mph in 6th. 4.1 would be just under 2000rpm which would be likely the best. Dropping dorren to 5th with your 3.55 should be about 2100 at 70mph.

Food for thought the raptors all come with 4.1 with the factory 35s. Even the older 6.2L versions did.

SlyFX4Guy

iTrader: (-1)

I tuned with 5 star.

I have 4" lift so 33 would look horrible

Running falken wild peak all terrain so not aggressive

Yes 3k for gear upgrade... :-/

I've dropped into 5th on hwy and put me at 2100 and mph was unchanged. 1800-1900 seems to be sweet spot.

Going to try the eco tune and see if it makes any difference.

Just bummed i didnt realize i had 3.55 not 3.73 until after i bought. Overlooked that detail

Munkeebutt

Wildpeaks are quite heavy! Probably about 80lbs each

Wade88

IIRC there's no way to get 3.73's from the factory with the 3.5tt.

white_dc

iTrader: (12)

^ This. Not sure size ring and pinon that comes in the Raptors/F150, but I'd imagine it should be possible to use factory takeoff parts to change your ratio to 4.10.