engineermike

I was driving the other day and noticed something interesting about the EB. Down at 1500 rpm in 6th gear, when you roll on the throttle (not WOT) it will develop 9-10 psi boost before unlocking the converter or downshifting. So, the motor is capable of making loads of low-end through boost, and the transmission is programmed to let it. That is all.

Mike

TruckLarry

That may be why the 3.55 has better 0-60 times than the 3.75 rear end does.

BassAckwards

Turbos like tall gears to push against.

GRWolverineFan

More load=More Boost

truckerdude

Therefore a 3.73 would put less load on the engine, not need as much boost and get better fuel mileage than the other rear end ratios.

Plus 3.73 has more get up and go so needs less fuel to get up and moving in city driving.

Summary: 3.73 should be the best axle for fuel economy

engineermike

I don't think that's how it works.

ssrbolt

I have the 3:15 gears in mine and it 60 ft'd a 2.08 which was pretty good. Ran 14.6 at 95 mph. Not sure how that'd compare to a 3:55 or 3:73 gear'd one. But yeah, turbo's tend to like the lower gears.

Papi4baby

Yeah no. You got it wrong.

If the truck is empty, is the other way around.

mrgt350

I would like to hear more on this with regards to mpg and gear ratio as I am trying to decide on a ratio for my EB I am close to ordering.

Actually the reason I like the 3.73 is for the e-locker which you can not get it in the 3.55's. I know of too many people that have had problems with the clutch packs in the limited slips.

truckerdude

the 3.73 will put less load on the engine, therefore it will pull more (it's own weight or with a load) with less boost THEREFORE mpg will be better

i will say it again. since its a lower rear end it takes less fuel to get moving, therefore better fuel mileage. only time that a higher rear end will help will be unloaded on flat ground then the 3.31 or 3.15 would do better- oh also better not be any wind blowing

understand?