Titan gear ratio mod

jmparker · 09-03-2006, 12:16 PM

Does anyone have any knowledge or experience in modifying the differential gear ratio to improve gas mileage? I assume there would be a trade off in pulling power but given the price of gas and the fact that I am not planning on pulling anything near 9500 lbs., is this a reasonable idea?

sudden urge · 09-03-2006, 12:48 PM

With the 2.94 rear, the OD kicks in at about 40 mph. and the RPM's are only about 1000. I can't see why you would want to be running lower than 1000 RPM's at 40 mph. Face the fact that the 2.94 is about as low as you can go.

MuskyHunter · 09-03-2006, 12:58 PM

Comparing the lower geared big tow vs. non big tow is good for about 1-2 mpg. Using the 2 mpg figure, and figuring that the big tow sees 16 mpg vs, 18 mpg, the per tank difference equates to 400 miles vs. 450 miles, or 50 miles per tank.

If you drive 20000 miles per year, you would use 1250 gallons for big tow vs. 1111 gallons, or a difference of 139 gallons. Using a cost of $2.75/ gallon, the cost savings of a non big tow vs. big tow is about $382.25/year.

With that said, assuming there was a gear swap available, you would have to look at your total cost of conversion, which would include all parts and any labor, then calculate your break even point. Also consider cost due to lack of parts availability because of the swap, should you break down on the road as you will no longer be stock, meaning longer delays in getting your vehicle back on the road.

Lastly, the gas mileage improvement may not be fully realized or as dramatic as anticipated after the swap, which would push out the break even number. You may end up being disappointed in how the truck drives after the conversion as it may be geared too tall and not much fun to drive anymore.

I wouldn't mess with the idea of a swap, but that would be your call.

Sniper · 09-03-2006, 01:08 PM

It also makes me wonder if the lower gears would keep it out of the power band and force it to downshift more often therefore destroying any possiblity of getting better gas mileage.

If you were looking for something good on gas, then you shoulda bought a Civic or something.....

pi3yeargrad · 09-03-2006, 02:49 PM

Quote:

Originally Posted by MuskyHunter

Comparing the lower geared big tow vs. non big tow is good for about 1-2 mpg. Using the 2 mpg figure, and figuring that the big tow sees 16 mpg vs, 18 mpg, the per tank difference equates to 400 miles vs. 450 miles, or 50 miles per tank.

If you drive 20000 miles per year, you would use 1250 gallons for big tow vs. 1111 gallons, or a difference of 139 gallons. Using a cost of $2.75/ gallon, the cost savings of a non big tow vs. big tow is about $382.25/year.

With that said, assuming there was a gear swap available, you would have to look at your total cost of conversion, which would include all parts and any labor, then calculate your break even point. Also consider cost due to lack of parts availability because of the swap, should you break down on the road as you will no longer be stock, meaning longer delays in getting your vehicle back on the road.

Lastly, the gas mileage improvement may not be fully realized or as dramatic as anticipated after the swap, which would push out the break even number. You may end up being disappointed in how the truck drives after the conversion as it may be geared too tall and not much fun to drive anymore.

I wouldn't mess with the idea of a swap, but that would be your call.

SO Im supposed to be getting 16mpg...man Ive never seen more than 12mpg and usually avg 9-11 mpg...

Mr. B · 09-03-2006, 03:05 PM

Quote:

Originally Posted by pi3yeargrad

SO Im supposed to be getting 16mpg...man Ive never seen more than 12mpg and usually avg 9-11 mpg...

I think I know why your fuel milage is abnormally low.......it's that 3000 pounds of assessories you have piled on your poor truck....it's probably way past it's weight limit and yet you continue to search high and low for more.

NorCal 4x4 · 09-03-2006, 04:03 PM

Quote:

Originally Posted by pi3yeargrad

SO Im supposed to be getting 16mpg...man Ive never seen more than 12mpg and usually avg 9-11 mpg...

Mr. B might have a point. What rims and tires are you running?

TitanBlue · 09-03-2006, 04:22 PM

Mileage was a bit of my concern when buying a big PU. Had a Ford Escape getting 18/22. Got an 06 Titan CC XE BT, get 15.5/19 with 4 people and a full bed of luggage at 80-85 mph. Can't complain about that with an 14/18 rating. Not worth losing what the Titan is all about to just gain really small increase. It would just destroy what it is designed to be , a Titan, not a Sentra. You would never enjoy the lost performacne and Capability of drastic gear change. Just mho.