I have a 2 week old Platinum eco 4wd with the 3.73 gears. I've seen 3.55 and 3.21 (if I rember correctly).

Can someone please explain the difference between the three different ratios and the effect it has in performance and gas mileage?

I do not do any towing, the 3.73 ratio just happen to come with the truck I purchased

Sorry for the newbie question. Thx!

 

The lower the number the slower acceleration will be but your top speed is higher.....and your cruising speed rpms will be lower netting better fuel mileage on the highway.

The higher the number is opposite of everything with the lower number. higher number is more acceleration but lower top speed and higher cruising rpms for worse highway fuel mileage.

Heavy towing big wheels and tires you want a higher gear.

Think of a ten speed pedal bike....might help make sense a lil for ya.

 

Acaps, good choice though. You got the best all around gear. The higher the gear (3.73/4.10)the easier for the towing at low end. The lower the gear (3.15,3.31.3.55)the better the highway travel. Since you don't tow and wanted good fuel the 3.15 would be ideal. For me towing a boat a lot I chose the 3.73 for the better ummff! off the line and up hills. This is course the laymens explanation,, the more technical guys will give you the details!! Enjoy your truck..

 

The 3.73 to 1 means that the drive shaft will make 3.73 revolutons which will make the axles turn 1 revolution. With the bigger number for the rear end gears (front also for 4X4's) the engine torque and HP will seem to be more and so will move a load easier.
As the RPM's will be higher, more gas will normally be used. More engine wear may also be possible as the engine will make more RPM's to go the same distance as the smaller number gears.

 

I would say that if there is the possibility of more engine wear from the higher rpms associated with higher ratios then trans wear would be greater with lower ratios since it is have to transmit more power to turn the wheels.

 

Consider yourself lucky...wish I had the 3.73 with my 5.0 much less one with an Eco. In my opinion much better performance in everyday use to get these heavy truck's rolling in city stop and go driving. With the high torque Eco engine your truck should be a beast! Any plan's to tow anything later or run some larger tires you'll be happy you have the 3.73's...in 6th gear on the highway gas consumption will be slightly more then with a 3.55 or 3.31 but overall the truck's performance will be much better.

 

Ok, I understand now. Thx all.

Loving the truck by the way, what a great vehicle.

 

3.55 seems to be most popular as it is a good balance. That and it is probably the "default" config on most dealer trucks. At least from what I see on the lots 3.73 is probably a close second.