3.08 = worthless?

[JimRummy]

Hey guys, im just trying to get a little clarification. I have a 2wd 4.0 with an open 3.08. I'm trying to figure out exactly why I have it, and what its good for, because 95% of what I read is"swap it for 3.55 3.73 4.10 " etc etc. I am just curious what 3.08 is good for since aapparently everything else is much better...
Thoughts?

 

[adsm08]

The 3.08 gears were available because engineers don't live or work in the real world.

On paper they make the fuel economy and emissions numbers look really good. In reality 3.73 tends to produce better results unless you live in Kansas.

 

[4x4junkie]

lol, even in Kansas 3.55:1 is likely to give better economy (not to mention better spunkyness ).

3.08 is the 2WD equivalent of the 3.27:1 gears used in 4x4s (equally worthless). Unless you're running some dinky little tires (P205/65R14 or something thereabouts), you'd be better off swapping to a 3.55 axle (stock P225 tires), or a 3.73 or 4.10 axle (30" or bigger tires).

Like said, it was to affect better CAFE numbers. They don't always translate well into the real world.

 

[JimRummy]

Bummer. Guess im SOL for a while. Kinda stupid IMO to have some geared some ways others geared another way. I mean I know engine and trans effect what it gets, and if its 2wd or 4 and whatnot, but I just dont get why the largest engine offered has the wackest gear ratio. I dont even get good mileage anymore and I cant figure it out. Replaced all the regular things that effect mpg but nothing has worked. Only thing I havent replaced is the O2 sensor, and that was only because I passed smog very easily.

 

[Insanejughead]

Your 3.08:1 makes Californistan politicians happy, though...

 

[Dune Runner]

3.08s are good for one thing and one thing only. Going 80 on the freeway. No good for anything else. I like 3.73s or 4.10s for anything bigger then 31s.

 

[JimRummy]

3.08s are good for one thing and one thing only. Going 80 on the freeway. No good for anything else. I like 3.73s or 4.10s for anything bigger then 31s.

You mean going 80 making a reasonable mpg, or going 80 in general? Like I said my mileage isnt stellar as is so losing a few mpg isnt that big a deal, but losing top speed altogether...

 

[Dune Runner]

3.08s are freeway gears. A lot depends on what tires you are running though. I run 3.73s with 31" tires and it's just right. You need to match your gears with what you do with the truck and the tires you are running. If all you do is drive 80mph all day and run little tires then 3.08s would be a good ratio. Otherwise no.

 

[JimRummy]

3.08s are freeway gears. A lot depends on what tires you are running though. I run 3.73s with 31" tires and it's just right. You need to match your gears with what you do with the truck and the tires you are running. If all you do is drive 80mph all day and run little tires then 3.08s would be a good ratio. Otherwise no.

Yeah Im running 30" tires. I do a lot of freeway driving but neved realized that the gearing was good for it. Its strange I went from 27 or 28" tires and it didnt effect mpg for a year, then it went from 19/25 mp to 14/17 mpg, maybe worse, and changing all the normal mpg effecting stuff and nothing helped. Must be the tires. I did go from 14 to 15" wheels too.
Just strange cause the mileage used to be great. It does haul ass though. The speedo stops at 85, but ive had the needle to OD on the gear shifter on some open desert highways ( I know, super responsible).