i have a 98 dodge ram 1500 5.2. am running 33'' on it, with k&n CIA and a flow master exhuast. if i switch my 3.55 gear with 4.10 will it help my gas mileage at all or with it make it worst? i live in the mountains and do must my driving on mountain freeways, lots of up and down. i get 13 mpg right now but am trying to make that a little better.

 

All depends.. I saw city improvement.. Highway it dropped off... Either way it is still a good idea to make the switch.. You will probably stay around 13 or 14 mpg though

 

in the hills you will notice a slight increase because it wont kick out of o/d as often on the up hills

 

The drive shaft will have to turn more times to make one revolution of the tire. No way can it improve gas mileage. And if one is driving up and down hills, OD should be off.

 

He's running 33s. So it actually might help. It would be like the stock ratio to tire size

 

driving in mountains and hills is fine to drive in o/d i have 300,000kms in the mountains in o/d original trans

 

While towing? And as a matter of fact, I believe even the owner manual tells you to turn off OD when going up big inclines, even without a load.

 

RPM isn't the only factor for gas mileage.

 

not that have found but even when towing I use od never have an issue

 

your mpg will drop to a little under 10mpg with 4.10s. thats what i got when i used to have my 33s, before i upgraded to 35s and it dropped further to 8.7mpg.