Hello all.

FNG here. Have a new-to-us 2013 F150 Scab. 3.5l Ecoboost.

As per the original window sticker, in addition to the "302A Equipment Group Package", the vehicle is equipped with the optional "3.31 Electronic Lock RR axle." Also the "7200# GVWR Package."

Can anyone explain:

1. Pluses and minuses of this axle ratio selection.

2. What exactly does the "7200# GVWR Package" include.???

Thanks much in advance. Really like this forum.

 

I've got the same rear end ratio with E-Lock and 7200# GVWR on my '13 Platinum.

The 7200# rating is for the weight of the truck plus payload. It's probably the most common rating other then the Max Payload package which allows for up to a 8200# GVWR.

The 3.31 axle ratio is mostly for lower rpm's at crusing speeds but doesn't pull as hard as a 3.55 or 3.73 would from a dead stop. The E-Lock rear option enables you to lock both rear wheels with a pull of the switch for better traction.

 

The axle ratio numbers can be confusing...lower numerical gear ratios are referred to as high meanwhile higher numerical gear ratios are referred to as low.

3.31 = high
4.10 = low

It refers to the ratio of revolutions of the fly wheel I believe...to the number of rotations of the wheel/driveshaft.

High gears have better fuel economy and a higher top end speed
Low gears have poorer fuel economy and a lower top end speed but offer you the ability to achieve power more quickly

The easiest way to think about it is in terms of the powerband/Engine RPM and how fast your tires are spinning.

Best example is with a low gear, like 4.10
With 4.10 gears, your engine RPM will increase more quickly under virtually all driving conditions, resulting in reaching the powerband more quickly and having more power sooner.

Usually, axle ratio comes into play for our sakes when people want to upgrade tire size.

 

Gear ratio would be driveshaft rotation to wheel rotation rather than flywheel speed. Other than that for the most part you are correct