Final Drive Ratio

[cdn87]

Did a search but didnt see any relevant results, might get flamed for this but I am looking at what it might cost to have higher (lower number) ratio diff's (all I have found is lower gears for offroad application like 4.10 and 4.55) installed and I can't seem to locate a brand or company that might carry something that would fit.

I am hoping to find maybe a 3.55 ratio to replace all final drive ratios in my 2005 V8 Limited. I understand stock is 3.73, trying to gain a few mpg's, who knows with price may not be worth while.

If anyone has any suggestions of where I might look please post a link.

Thanx.

 

[TRDCal]

x2 I'm curious about this as well. Sorry I don't any info to add but at least if you get flamed, I can take some of the blame hahaha

 

[03_4x4Runner]

I doubt you would gain any mpg and even if you did it would take a lot of savings to pay for the swap. Acceleration would not be as good either.

 

[CXS]

x2, interesting theory worthy of discussion but the return on investment would be far too small to make it worthwhile.

 

[settytb]

Also, the factory gears it to get best mpg's anyways. They don't gear it to be a racecar. I doubt changing the ratio would help. I got taller but skinnier tires 255/75/17 and it changed my gearing slightly making it a taller gear and that didn't help my mileage at all...

 

[TRDCal]

Also, the factory gears it to get best mpg's anyways. They don't gear it to be a racecar. I doubt changing the ratio would help. I got taller but skinnier tires 255/75/17 and it changed my gearing slightly making it a taller gear and that didn't help my mileage at all...

I don't think the factory gears are designed for best of anything let alone mpg. When engineers were picking gears they have alot of factors to consider like towing, acceleration, drive ratios as well as how these factors will react in different landscapes/climates. I think the engineers have to find a happy medium between all these factors to keep everyone happy.

 

[cdn87]

The reason this idea came up was I owned a 1997 Explorer a few years ago and on a forum for Explorers I learned that the factory had atleast 2 sets of gearing options to choose from when ordering (3.55 or 3.73) and there was a significant difference in fuel economy between the two (I understand there are alot of factors that come in to play with MPG differences) those who had a 3.55 final drive always had higher MPG stats than those with 3.73 (of course comparing apples to apples with same engine configuration and number of driven axles etc.)

 

[mckbrew]

Wow, I've never heard of anyone re-gearing in that direction. Think about everything that you would need to do esp with a 4 runner without a programmable ECU. Unlike some vehicles it is far more difficult to re-calibrate your speedometer/odometer to read correctly and without doing that you'll have no idea what the gains if any will be.

First of all the factory gears are designed with the tires, wheels, and everything else in mind. People re gear to lower ratios in order to run heavier rims, bigger tires, etc... In most applications the higher gear ratios are offered on vehicles that have smaller wheels and tires.

Figure a gear install is probably going to run anywhere from 800-2000 depending on where you live and what companies are in your area. More than likely the difference between 3.73 and 3.55 (with correct sized tires and all) is only going to be a few mpg at most. It will take a long time to re-coup that cost at the pump.