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Old 11-30-2006, 08:52 PM   #21
chadvicki
Registered User
 
Join Date: Nov 2006
Location: California
Posts: 87
Re: I am so confused. Please help.

Quote:
Originally Posted by mrein3 View Post
Contrary to what many above have posted, you can tow all day long with a 700r4, just don't use overdrive. 3rd gear in a 700 is the same 3rd and final gear in a th350. If you are running a tranny cooler and watching your temp you can tow just as much as a 700r4 in 3rd as you can in a th350.

Overdrive on a 700r4 is .7 to 1. In other words you have a 30% drop off in your rpms when on the freeway in OD. (Not exactly but close enough for state work).

ALL factory rear end gears are 10% different then the next size. To go from a 4.11 to a 3.73 rear you will have 10% less rpms at the same speed as the guy with the 4.11. 4.56 to 4.11 is 10%. 3.08 to 3.43, 10%. 3.43 to 3.73, 10%.

Change two gear sizes is 20% (not exactly but again close enough for state work). Three sizes is close enough to 30% to just call it 30%.

SOOOOOoooo...
If you have 4.11s now and switch to 3.08, you achieve effectively the same change in highway rpms as getting a 700r4.

Switching from 28 inch tall tires to 33 inch tall tires will decrease your highway rpms approximately 20%.

What do you want to do with the truck? All this stuff costs money. If you drop $1000 on a new tranny, how much gas can you buy for $1000? How long does it take to "get back" your investment? I've driven 2000 miles in 4 years in my truck. 200 gallons over 4 years is real hard to justify a 700r4 just to save money.

A Prius that gets 50mpg? I've don't know anybody who gets over 35mpg in their Prius'. Or are two Prius' referred to as Prii?
Thanks everyone for your comments and help.

mrein3

I use this truck as a daily driver. I haul nothing and never tow. I drive about 100 miles a day sometimes less. All freeway. Right now I am getting about 11mpg and I have a 20 gallon tank. Is the 700r4 on Ebay? It looks like it is.

I just cant do it myself is the prob. I would like to get 15mpg if possible. I have new tires and wheels now. 265/75-16 radials. If I change the gearing to a 3.73 do I need to get a bigger housing?

Maybe it just needs to be left alone. I just hate getting only 150 miles to a tank of gas. (approx 150 miles)

Chad
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