35s and 3.08s

[Luka Mahovac]

I’m looking into lifting my truck and going with some bigger tires and found a good deal on some 35x12.50r20s. Wondering if anyone is running 35s on a 5.3 with 3.08 gear ratio. Mainly interested in fuel economy and if you have any tune or upgraded intake thanks.

[MikeBMW]

13 minutes ago, Luka Mahovac said:

I’m looking into lifting my truck and going with some bigger tires and found a good deal on some 35x12.50r20s. Wondering if anyone is running 35s on a 5.3 with 3.08 gear ratio. Mainly interested in fuel economy and if you have any tune or upgraded intake thanks.

Mine has a 5.3 with a 3.42 rear. After the 35s, I was lucky to get 10 MPG.
I did do a tune via FlashPaq F5, reset the tire size and I'm up to 11.2 MPG or so. Most of my driving is on city roads.
Bigger tires will always hurt your MPG no matter what tune you throw at it but correcting tire size in the ECU helps correct a bit of it.
If MPG is your biggest concern, don't get bigger tires, a lift, etc.
 

Edited September 28, 2021 by MikeBMW

[Tony Barry]

You need to regear to 4.10 gears or even better 4.56's ...you will lose all your power and mileage if you don't ....33's are okay if you have 3.42 or 3.73 though

[MikeBMW]

8 minutes ago, Tony Barry said:

You need to regear to 4.10 gears or even better 4.56's ...you will lose all your power and mileage if you don't ....33's are okay if you have 3.42 or 3.73 though

Nah, I'm not worried about MPG and, after the tune, this thing runs great with the 3.42s and 35s.

[CamGTP]

If he has a 6 speed auto, go with 3.73's. 8 speed auto could be 3.73's or 3.42's.

 

Can someone go with 4.10's, yeah but it's not as needed with the more gears the transmission has. All the 4 speed auto's would need 4.10's at a minimum with 35's just to make it drive way better.

[dieselfan1]

I'm  on a 10.5" lift with 38s with the 5.3 3.42. It turned the gearing to around 2.90. Like Mike BMW I have a Superchips Flashpaq F5 tuner that helps some. I'm getting 13-14 mpg driving like a Grandpa. I am a Grandpa so I don't care.

I'm thinking 35s w 3.08s would be something in the 2.70-2.80 range.

Not good.

I'm at the absolute limit at 2.90 IMO. I think anything less would be a real dog.

Edited September 28, 2021 by dieselfan1