Anyone with a double cab switched to higher rear end ratio. results.

[oldtech]

I have a 2005 tundra double cab. I read somewhere that the double cab has a 390 rear end ratio and the access cab has a 360 ratio. We only pull 2000 lbs occasionally . Would like to hear from anyone who has made the change and did you pick up any mpg. Thanks

[tundra3400]

well the 2005 DC do come with 390s but the 2005 AC dont come with 360 they come with 376s in the SR5 2WD models. the 4WD and limited models come with 390s. changing up ratios may give you more gas mileage but it will kill power.

[Highwaylizard]

I have a 2005 tundra double cab. I read somewhere that the double cab has a 390 rear end ratio and the access cab has a 360 ratio. We only pull 2000 lbs occasionally . Would like to hear from anyone who has made the change and did you pick up any mpg. Thanks

I went from the stock 4.10 gearing to 3.90, not entirely by choice (but that is a story for another time), and picked up a little mileage. I used to own and operate a landscaping company and tree service and never had a problem pulling trailers anywhere from 3,000 pounds to well over 7,000. I was able to switch the differentials at minimum cost due to the kindness of a couple of members here who sold me theirs at very reasonable cost.

[tundrunk]

The only stock ratios I've ever heard of in Tundra's is 3.91 or 4.10, never heard of 3.60 or 3.76...
T100's came with 4.30 though.

[Highwaylizard]

The only stock ratios I've ever heard of in Tundra's is 3.91 or 4.10, never heard of 3.60 or 3.76...
T100's came with 4.30 though.

Me too - but then again this is not my department.

[skilife]

Just so we're clear...
Going with a "lower" # ie 3.91 like in my '05 DC vs. 4.10, 4.30, would mean less power (because of the ratio) better mileage right? Higher # better power less mileage??? Kind of thinking like a manual transmission, the higher the gear you shift into the less power but better mileage... I guess that's what I thought is the purpose of regearing was when you put on bigger tires... (maybe I can learn something here)
Oldtech- What are you wanting to do?

[tundra3400]

The only stock ratios I've ever heard of in Tundra's is 3.91 or 4.10, never heard of 3.60 or 3.76...
T100's came with 4.30 though.

and the V6 auto tundra comes with 430s. my tundra has em.

this site has all the gear ratios for toyota vehicles: Toyota Motor Company Axle Gear Ratios

[tundra3400]

Just so we're clear...
Going with a "lower" # ie 3.91 like in my '05 DC vs. 4.10, 4.30, would mean less power (because of the ratio) better mileage right? Higher # better power less mileage??? Kind of thinking like a manual transmission, the higher the gear you shift into the less power but better mileage... I guess that's what I thought is the purpose of regearing was when you put on bigger tires... (maybe I can learn something here)
Oldtech- What are you wanting to do?

thats correct skilife.

[BamZipPow]

Here's a listing of what differential ratios that came with the T-100...on www.car-part.com.

1993 Toyota T100 (6cyl = 3.0L engine)
Carrier

Rear Axle, (6 cyl), 4x2, 1 ton, ABS, AT (4.70 ratio)
Rear Axle, (6 cyl), 4x2, 1 ton, ABS, MT (4.46 ratio)
Rear Axle, (6 cyl), 4x2, 1 ton, w/o ABS; AT (4.70 ratio)
Rear Axle, (6 cyl), 4x2, 1 ton, w/o ABS; MT (4.46 ratio)
Rear Axle, (6 cyl), 4x2, 1/2 ton, ABS, AT (4.27 ratio)
Rear Axle, (6 cyl), 4x2, 1/2 ton, ABS, MT (4.08 ratio)
Rear Axle, (6 cyl), 4x2, 1/2 ton, w/o ABS; AT (4.27 ratio)
Rear Axle, (6 cyl), 4x2, 1/2 ton, w/o ABS; MT (4.08 ratio)
Rear Axle, (6 cyl), 4x4, ABS, 4.46 ratio (MT)
Rear Axle, (6 cyl), 4x4, ABS, 4.70 ratio
Rear Axle, (6 cyl), 4x4, ABS, 4.90 ratio (AT)
Rear Axle, (6 cyl), 4x4, w/o ABS; 4.46 ratio (MT)
Rear Axle, (6 cyl), 4x4, w/o ABS; 4.70 ratio
Rear Axle, (6 cyl), 4x4, w/o ABS; 4.90 ratio (AT)


1994 Toyota T100 (6cyl = 3.0L engine)
Carrier

Rear Axle, 4 cyl, ABS, 3.62 ratio
Rear Axle, 4 cyl, ABS, 3.77 ratio
Rear Axle, 4 cyl, w/o ABS; 3.62 ratio
Rear Axle, 4 cyl, w/o ABS; 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1 ton, ABS, AT (4.70 ratio)
Rear Axle, 6 cyl, 4x2, 1 ton, ABS, MT (4.46 ratio)
Rear Axle, 6 cyl, 4x2, 1 ton, w/o ABS; AT (4.70 ratio)
Rear Axle, 6 cyl, 4x2, 1 ton, w/o ABS; MT (4.46 ratio)
Rear Axle, 6 cyl, 4x2, 1/2 ton, ABS, AT (4.27 ratio)
Rear Axle, 6 cyl, 4x2, 1/2 ton, ABS, MT (4.08 ratio)
Rear Axle, 6 cyl, 4x2, 1/2 ton, w/o ABS; AT (4.27 ratio)
Rear Axle, 6 cyl, 4x2, 1/2 ton, w/o ABS; MT (4.08 ratio)
Rear Axle, 6 cyl, 4x4, ABS, 4.46 ratio (MT)
Rear Axle, 6 cyl, 4x4, ABS, 4.70 ratio
Rear Axle, 6 cyl, 4x4, ABS, 4.90 ratio (AT)
Rear Axle, 6 cyl, 4x4, w/o ABS; 4.46 ratio (MT)
Rear Axle, 6 cyl, 4x4, w/o ABS; 4.70 ratio
Rear Axle, 6 cyl, 4x4, w/o ABS; 4.90 ratio (AT)


1995 Toyota T100
Carrier

Rear Axle, 4 cyl, AT, 3.91 ratio
Rear Axle, 4 cyl, AT, 4.08 ratio
Rear Axle, 4 cyl, MT, 3.62 ratio
Rear Axle, 4 cyl, MT, 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1 ton (3.91 ratio)
Rear Axle, 6 cyl, 4x2, 1/2 ton, 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1/2 ton, 3.91 ratio
Rear Axle, 6 cyl, 4x4, AT, 4.10 ratio
Rear Axle, 6 cyl, 4x4, AT, 4.30 ratio
Rear Axle, 6 cyl, 4x4, MT, 3.91 ratio
Rear Axle, 6 cyl, 4x4, MT, 4.10 ratio


1996 Toyota T100
Carrier

Rear Axle, 4 cyl, AT, 3.91 ratio
Rear Axle, 4 cyl, AT, 4.08 ratio
Rear Axle, 4 cyl, MT, 3.62 ratio
Rear Axle, 4 cyl, MT, 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1 ton (3.91 ratio)
Rear Axle, 6 cyl, 4x2, 1/2 ton, 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1/2 ton, 3.91 ratio
Rear Axle, 6 cyl, 4x4, AT, 4.10 ratio
Rear Axle, 6 cyl, 4x4, AT, 4.30 ratio
Rear Axle, 6 cyl, 4x4, MT, 3.91 ratio
Rear Axle, 6 cyl, 4x4, MT, 4.10 ratio


1997 Toyota T100
Carrier

Rear Axle, 4 cyl, AT, 3.91 ratio
Rear Axle, 4 cyl, AT, 4.08 ratio
Rear Axle, 4 cyl, MT, 3.62 ratio
Rear Axle, 4 cyl, MT, 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1 ton (3.91 ratio)
Rear Axle, 6 cyl, 4x2, 1/2 ton, 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1/2 ton, 3.91 ratio
Rear Axle, 6 cyl, 4x4, AT, 4.10 ratio
Rear Axle, 6 cyl, 4x4, AT, 4.30 ratio
Rear Axle, 6 cyl, 4x4, MT, 3.91 ratio
Rear Axle, 6 cyl, 4x4, MT, 4.10 ratio


1998 Toyota T100
Carrier

Rear Axle, 4 cyl, AT, 3.91 ratio
Rear Axle, 4 cyl, AT, 4.08 ratio
Rear Axle, 4 cyl, MT, 3.62 ratio
Rear Axle, 4 cyl, MT, 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1 ton (3.91 ratio)
Rear Axle, 6 cyl, 4x2, 1/2 ton, 3.77 ratio
Rear Axle, 6 cyl, 4x2, 1/2 ton, 3.91 ratio
Rear Axle, 6 cyl, 4x4, AT, 4.10 ratio
Rear Axle, 6 cyl, 4x4, AT, 4.30 ratio
Rear Axle, 6 cyl, 4x4, MT, 3.91 ratio
Rear Axle, 6 cyl, 4x4, MT, 4.10 ratio

This is what they are showing fer the 2005 Tundra...

2005 Toyota Tundra
Carrier

Front Axle, (8 cyl, 3.91 ratio)
Rear Axle, 6 cyl (3.77 ratio)
Rear Axle, 8 cyl, 4x2, 3.62 ratio, locking (posi)
Rear Axle, 8 cyl, 4x2, 3.62 ratio, w/o locking
Rear Axle, 8 cyl, 4x2, 3.92 ratio, locking (posi)
Rear Axle, 8 cyl, 4x2, 3.92 ratio, w/o locking
Rear Axle, 8 cyl, 4x4, (3.91 ratio), locking (posi)
Rear Axle, 8 cyl, 4x4, (3.91 ratio), w/o locking

...and fer the 2004 Tundra.

2004 Toyota Tundra
Carrier

Front Axle, 6 cyl, AT (4.30 ratio)
Front Axle, 6 cyl, MT (4.10 ratio)
Front Axle, 8 cyl, 3.91 ratio
Front Axle, 8 cyl, 4.10 ratio
Rear Axle, 4x2, 6 cyl (4.08 ratio)
Rear Axle, 4x4, 6 cyl, AT (4.30 ratio)
Rear Axle, 4x4, 6 cyl, MT (4.10 ratio)
Rear Axle, 4x4, 8 cyl, 3.91 ratio, locking (posi)
Rear Axle, 4x4, 8 cyl, 3.91 ratio, non-locking
Rear Axle, 4x2, 8 cyl, 3.91 ratio, locking (posi)
Rear Axle, 4x2, 8 cyl, 3.91 ratio, non-locking
Rear Axle, 4x2, 8 cyl, 4.08 ratio, Double Cab (4 Dr), locking (posi)
Rear Axle, 4x2, 8 cyl, 4.08 ratio, Double Cab (4 Dr), w/o locking
Rear Axle, 4x2, 8 cyl, 4.08 ratio, w/o Double Cab
Rear Axle, 4x4, 8 cyl, 4.10 ratio, Double Cab (4 Dr), locking (posi)
Rear Axle, 4x4, 8 cyl, 4.10 ratio, Double Cab (4 Dr), w/o locking
Rear Axle, 4x4, 8 cyl, 4.10 ratio, w/o Double Cab

[tundrunk]

Just so we're clear...
Going with a "lower" # ie 3.91 like in my '05 DC vs. 4.10, 4.30, would mean less power (because of the ratio) better mileage right? Higher # better power less mileage???

It isn't as simple as that but you are on the right track, the power part is essentially correct. It seems fair to conclude that at any given speed (lets say 60mph) the lower the RPM your motor spins at, the less fuel you will consume. The logic would be that since your motor is spinning less, it is completing less combustion cycles and therefore burning less fuel. The problem with that logic is that your motor doesn't consume the same ratio amount of fuel per combustion cycle at 1500 as it does at 2500. There is a sweet spot for your 4.7L to run at its best efficiency, and depending on several variables (weight, gearing, motor modifications, air temperature, altitude, wind resistance, road grade, etc) the sweet spot will be different for different trucks.

For example, my truck has 285/75/16 tires, headers/exhaust and carries an extra 200lbs give or take not counting me. When I ran on 3.91 gears, my highway averages were in the 17-18mpg range running around 65-70MPH with an RPM range from 1600-1900. I later went to 4.56 gears and my highway average is up to 19-20mpg range running 65-70MPH with RPMs running between 2200-2400. Sounds counter intuitive right? The secret is that my motor was previously operating at a range where the torque power band wasn't optimal, the term used by hot rodders would be "bogging". It now is in a very good power band and uses less fuel to motivate my truck. I can actually touch on 21-22MPG on longer highway trips now provided the right weather and traffic conditions as long as I stay around 68MPH. That's Highwaylizard territory but with a lot of mods that should be killing my gas mileage, in Toby's defense he does have a larger and heavier truck since he had a 4x4 DC and I have a 2WD AC.

I don't know enough about the Tundra's ignition system, fuel system or valve operation to understand all of the variables. There are a lot of factors to consider when it comes to fuel efficiency, but in my case the lowered (or numerically raised) gear ratio worked in my favor for operating with more power available and better fuel economy. Lizard has increased fuel economy by going with higher gearing (numerically lower) which I would assume is because he stuck to a more reasonable tire size than I did.

Thanks for that info Bamzippow, nice to learn something new. Now I'm curious if Tundras with the 3.62 gears were only offered with the 245 tires, those don't seem very common. Points on the way if I'm able to send.

[skilife]

Old tech,

I at some point will be doing 4.56 front/rear in mine. (expensive? YES!!) I'm going up and doing bigger tires so I can't comment now as to how it will affect anything but....
I wouldn't think you would really need a regear if only towing 2k "occasionally"
But what's the point in what you really need and what you want?!!!!
I don't NEED to buy bigger tires, buy and get the diffs removed, rebuilt, and replaced, buy pretty much a whole new suspension for what I WANT but I WANT to.... Because every vehicle I've ever owned has had something done to it...It's fun!

Great info Drunk! and everyone else!
DAMN I love this site!

[tundrunk]

I don't think I've NEEDED to do anything I've done to my truck, it was all WANT... except my rear end rebuild because that was blown out.

[RingSteel]

When I ran on 3.91 gears, my highway averages were in the 17-18mpg range running around 65-70MPH with an RPM range from 1600-1900. I later went to 4.56 gears and my highway average is up to 19-20mpg range running 65-70MPH with RPMs running between 2200-2400.

Thanks for the great real-world info!

Was it difficult to get your speedo re-calibrated to match the new gearing?