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final gear ratio - 04 big tow vs 08 non big tow

22K views 17 replies 15 participants last post by  dogstar 
#1 ·
I noticed on my 04 titan (w/ big tow package) while crusing in 5th gear on the highway at 70mph, the tach would sit right around 2k RPMs. however, my on my 08 (w/o big tow), it won't reach 2k until about 80+ mph. ...at 70mph, RPMs sit around ~1400.


Question, is something to do with the big tow package's different final gear ratio, or did something change with the 08 models? regardless, I love it!!! ...makes for a much quieter ride, I'm sure it's saving gas....plus it's got to be better on the truck, since I tend to drive 'faster' on the highways.
 
#2 ·
I know my 08 pro4x has 3:36 final g/r which is the same as 4:10 rear end dont know about urs though ill investigate
 
#3 ·
Yes it's the different gear ratio that is keeping your rpms lower at any given speed vs. the BT. Nothing else.

I want to say the non-BT ratio is 2.9(something):1
 
#4 ·
eurohazard said:
Yes it's the different gear ratio that is keeping your rpms lower at any given speed vs. the BT. Nothing else.

I want to say the non-BT ratio is 2.9(something):1

non-BT is 2.94:1 while BT is 3.36:1
 
#5 ·
That is a 12.5% reduction from what you had. Definetly going to help highway mileage, but not sure about around town. The engine will lug a bit in town.
 
#6 ·
I've had both as well and there is a definite advantage to each differing gear set. Around town the 3.36 seems to get better fuel economy and perform better, likely because the transmission multiplies the engine torque a greater degree than non BT, making stop and go accelerating less load on the engine. At highway speeds, the non BT obviously out performs the BT in fuel economy by dropping the RPM. Acceleration with the VK's power charachteristics tends to favor the non BT gears at higher speeds because the truck spends a great deal more time in its peak power range rather than reaching towards the stratosphere out of its power range. Dropping the hammer at freeway speeds with the non BT gears plops the RPM's right in the sweet spot and allows the motor to do its best work. Do the same with the BT gears and you make a lot of noise until it shifts.
 
#7 ·
has neone tryd 3.55 gears? race a mustang with them and he was srtong off the line
 
#8 · (Edited)
rebel1305 said:
has neone tryd 3.55 gears? race a mustang with them and he was srtong off the line
There are none available for a Titan.

CABPRO4X said:
I know my 08 pro4x has 3:36 final g/r which is the same as 4:10 rear end dont know about urs though ill investigate
The 3.36 is not the same as a 4.10.
Since we have a five speed transmission first gear is lower than many other vehicles. Therefore the overall gear ratio in first gear in the Titan is similar to other vehicles with a four speed transmission and a 4.10 rear ratio.
 
#9 ·
Our first three gears go through the range that other trucks only do in two. Our forth gear is about the same as their third (1 to 1), and fifth about the same as their forth (OD).
 
#10 ·
Big Tow vs std ratio

The "Big tow" package includes a 3.36 ratio differential. The non-Big tow trucks include a 2.94 ratio differential. The difference is about 10 MPH at 2K rpm, and about 3.5-4 MPG.

IF you trick up the truck with bigger tires, you also change the ratio; many modified 2.94 trucks need the 3.36 to offset the tire size shift and maintain the original ration and speedo readings.

Big tow is stronger; if you tow heavy, you need it.

Spiritgide
 
#12 ·
Big tow-

Not sure if the 2010 would be different than mine or not. Possible.

IF your highway rpm is near 2000 at 70 mph, it indicates a 3.36 ratio rear end, which is the big tow version. 2000 at 80 mph indicates 2.94 axle, or the standard truck.

IF you have a switch on the dash (low center below radio) that says "Tow mode" it should have the big tow package.

Also, could give a nissan dealer your vin, that should allow them to tell you what the equipment list is for your truck.

Spiritgide
 
#13 ·
spiritgide is correct about the rpm numbers for the big tow at 70 and non-big tow at 80, as I also have the 2wd w/out big town and cruise around 2000 rpm @80. However, unless the newer models have changed, I believe all the Titan's have the "Tow Mode" button, as I know I do! Other ways to tell if you have big tow, is the larger mirrors and the trans temp gage came with that package on most of the previous model Titans. Hope this helps answer your questions!
 
#18 ·
spiritgide is correct about the rpm numbers for the big tow at 70 and non-big tow at 80, as I also have the 2wd w/out big town and cruise around 2000 rpm @80. However, unless the newer models have changed, I believe all the Titan's have the "Tow Mode" button, as I know I do! Other ways to tell if you have big tow, is the larger mirrors and the trans temp gage came with that package on most of the previous model Titans. Hope this helps answer your questions!
The tow mode is not the Big Tow package. It is a transmission re-mapping tune, not different gears that IMO wasn't worth the effort.
 
#15 ·
Old old topic....I know, I know,......but I do have something to add that I've not seen anywhere else. I have an 05 LE CC with Big Tow on the build sheet and online VIN decoders. I have all the indicators in the cab and elsewhere....including 70 mph at 2000 rpm.

Except the door pillar card shows the axle as a CC29...which is for a 2.94 axle!

Now for all those who want to know for once and final, regardless of tires or anything else...here's the how to:
Put the rear drive wheel up off the ground so you can spin it freely.
Put a mark on the inside of the wheel and a mark on the drive shaft with a tire crayon or such.
Rotate the tire one full revolution.
If the mark on the drive shaft comes up short of three full...it's a 2.94. Go past 3 full.....it's a 3.36

Lower your truck to the ground and enjoy it.
 
#16 ·
I would tend to believe the door sticker, not sure why they would've put the highway gears in a Big Tow truck though. Have you run this test to confirm?
 
#17 · (Edited)
Yes. It's a trick from my gearhead youth (late 60's) when junkyard axles weren't easily identified. It will eliminate any question and can be done in the yard before you pick. I bought my truck used and it was my first Titan. When I saw the sticker, I was livid since I pull a 9000 lb set up. Did my test and now I sleep at night. Nissan dealers aren't too skilled at knowing much about their products I've since found out. High turnover in the auto industry has created pure BS conversations about everything in one.
 
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