baxzilla

iTrader: (2)

Building my truck the the way I want it:
Lariat CC 6.5' FX4 5.0 502A etc. I am looking at leveling down the road with BFG K02 285/65/20 tires. I was leaning towards the 3.55 for MPGs but is there really much of a difference between the 3.55 and the 3.73 fuel mileage wise?

Also can you really not get snow plow prep with the 502A?

savagecanuck

I had a 4sp auto 4.10 5.3 08 silverado currently have a 14 with 3.42 5.3 DI silverado 6spd. Maybe 1 mpg different over lifetime. No real penalty for the 3.73 gears. I ordered 5.0 with 3.73

flanneljunkie

The difference in ratio will be negligible. Outside factors will contribute to fuel economy much more than the small difference in gear ratio.

For what it's worth, the 3.73 really proved themselves nice for me in city stop and go traffic and 2 lane, twisty, mountainous roads. On the highway, I still cruised at 65mph at about 1700 rpm or so while hitting about 20mpg.

Seed

I have almost the same truck and have those tires on it with the 3.73. Mileage sucks. 14MPG average for around town. Even on the factory tires mileage was pretty rough. Maybe it will smooth out over time but I would say marginally at best. No idea if it's cause of the 3.73. I'd say prob not by much if any.

LCW

I had 3.73 on my 2011 5.0 and now 3.55 on my 2015. Glad I made the switch. I figured lighter truck and more power I wanted more economy with still decent accel. I almost went 3.31 but glad I went 3.55. The lower cruising RPM vs the 3.73 is nice too.

Unless you're towing over 50% of the time, you don't really need the 3.73 on the '15 imo.

Wis_Skier_23

He wants to run a 34" tire so that 3.73 turning a bigger tire will act like a 3.5 after everything is said and done. That's the reason why I got the 3.73. Besides what's a .5 mpg really shake out to cost wise after all is said and done. I'd rather have more low end power and happiness vs saving more at the pump. I can do that by adjusting how hard I get on the pedal.

ddeevers

Probably not with stock tires. Going to 35's 3.73 will help with acceleration, mpg's and less strain on parts. With 35's and 3.73 you will probably get better mpg's all around than with 3.55.

namrogd

[QUOTE=baxzilla;4130501]Building my truck the the way I want it:
Lariat CC 6.5' FX4 5.0 502A etc. I am looking at leveling down the road with BFG K02 285/65/20 tires. I was leaning towards the 3.55 for MPGs but is there really much of a difference between the 3.55 and the 3.73 fuel mileage wise?

Also can you really not get snow plow prep with the 502A

LCW

Ah - if the desire is running 35's I can see wanting 3.73's.

Halfshell1

3.73s