Rear diff gear ratios and mileage?

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BigBlock	Rear diff gear ratios and mileage?	Lead	[-]
Posts: 5 (02/14/09 01:06 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Tags : None We bought an '03 Frontier with the 3.3 and manual trans for my wife several months back and have really enjoyed it. I was a little dissappointed in the fuel mileage, but from what I've been reading on here, it's getting better than most (averaging about 19 mpg). Her previous vehicle was a '97 Nissan with the 2.2 four and manual trans. and it got better mileage. I don't know why I expected the new truck to do about the same with a V-6 and two more doors; it's gotta be a lot heavier, so I guess overall, it's doing pretty well. My question though, is this: has anyone ever played with rear gear ratios on these things? At 70 mph, the engine's running at 3000 rpm. For all I know, that's the sweet spot in this engine and the best it's going to do. It's just that, at least by the seat of my pants, it feels like this engine has way more torque below 2000 rpm than at 3000, and if it could keep the vehicle cruising at speed in that range, it should get way better mileage. I know that most modern vehicles with V-8's (I realize, a completely different application) cruise at 70 mph at 1800 rpm. Maybe the 3.3 doesn't have the torque to keep up and has to depend on horsepower? Anybody experiment with this? Thanks... Don
Mathster		#1	[-]
Posts: 4877 (02/14/09 10:39 PM) Crazy Member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	3000 rpm with my automatic is about 80 and yes, its a sweet spot. Could probably do better faster, but im not brave enough to push more than 5 or 10 over. I have towed several times with my truck and getting between about 2300 to 2800 is just a dog. outside of that range, it pulls great. There aren't many options for these trucks as far as gearing goes without doing an axle swap. The gen 2 frontiers will run less than 2000 rpms at 70 (with the automatic). The gen 1 frontiers have the power of a 4cyl with the fuel mileage of an 8. A little better than 19 is what Im averaging. While you didn't realize it, the National Anthem does end with "Gentlemen Start Your Engines!"
Redneck		#2	[-]
Posts: 2 (02/18/09 08:37 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	dont quote me on this and I'm sure someone else knows more about it. I have the same truck and my rear gears are 4.63, axle is the h233b. I think someone mentioned in another post I read that the Pathfinder come with 4.36 in the same axle that would drop the rpms but would sacrifice elswhere (I.E fuel milage in town, and take off from stop) I would like to try this myself but lacking funds. I used this link for some info but I've heard it's not total accurate. http://www.nicoclub.com/Greg/ratios.html 31 x 10.50 hibdon specials.resonator removed
BigBlock		#3	[-]
Posts: 7 (02/19/09 12:49 AM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Wow! According to that chart, there's some real high gear ratios in these things. I'm not worried so much about around town driving. You can get away with starting out in 2nd gear in our truck. 1st runs out of breath before you get moving. It doesn't look like there's many options out there for lower ratios; that said I see there was a 3.63 or something like that available for the one axle in '05. I don't know which axle is in our truck. Anybody know how to quickly ID which axle I have? Maybe it's indicated on the housing? Thanks... Don
Mathster		#4	[-]
Posts: 4881 (02/19/09 10:28 PM) Crazy Member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Automatic Transmission gear ratio (1st) 2.79 Transmission gear ratio (2nd) 1.55 Transmission gear ratio (3rd) 1.00 Transmission gear ratio (4th) .69 Transmission gear ratio (reverse) 2.27 Manual Transmission gear ratio (1st) 3.32 Transmission gear ratio (2nd) 1.90 Transmission gear ratio (3rd) 1.31 Transmission gear ratio (4th) 1.00 Transmission gear ratio (5th) .84 Transmission gear ratio (reverse) 3.38 Source: www.cars.com It looks like the manual transmission is geared a bit lower than the automatic transmission. If your 2wd, you might look into a dual range / overdrive conversion. I dont think you will find one that will marry up on a 4x4. While you didn't realize it, the National Anthem does end with "Gentlemen Start Your Engines!"
Redneck		#5	[-]
Posts: 4 (02/19/09 11:31 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	check the tag on the drivers side door pillar probubly says h46 or something like that 03 CC SB V6 5 speed 31 x 10.50 hibdon specials, .resonator removed, homeade T handle shift knob When all else fails read the direction!
Redneck		#6	[-]
Posts: 5 (02/19/09 11:39 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	only overdive unit Ive found are gear vendors and and us gear. all a little pricy for me 03 CC SB V6 5 speed 31 x 10.50 hibdon specials, .resonator removed, homeade T handle shift knob When all else fails read the direction!
BigBlock		#7	[-]
Posts: 8 (02/20/09 01:00 AM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Mathster, yeah it's a two-wheel drive. I was thinking I could find an axle with a different gear ratio and that would probably be cheaper than the overdrive unit. However, I don't really want to spend a bunch of money only to find out that the engine can't pull the truck at speed at that low of RPM's. Redneck, according to the chart you posted the website for, there were two different axles available on my truck: H233B & C200. I'm not sure how to tell which one of these is in my truck. It's a 2 wheel drive, hmmm, maybe one is 4x4? The door pillar tag you're talking about sounds like it might tell me what the gear ratio is? I'm with you on the overdrive unit; a little pricey. On the other hand, I've been really doing some searching and it doesn't sound like anybody even makes gearsets for these things. I guess I'm used to GM and Mopar; I can get gearsets in just about any ratio I desire for around $200 if I'm not going racing. But there just isn't any for these Nissans. I did notice that the '05 Frontier had the C200 axle in it with an available 3.63 or something close to that. If my truck has that axle in it, I could maybe start searching the junkyards for one of those. I was hoping that someone on here had already tried this and they could just tell me if it was worth the effort. I'm cheap that way, I guess. Ha! Thanks guys for your input! Don
Mathster		#8	[-]
Posts: 4882 (02/20/09 08:03 PM) Crazy Member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	you could probably safely spin a ford 9 inch. you gotta remember, at 170 HP and 200 ft-lbs torque, our engines are about as powerful as 1/2 ton trucks of 40 years ago. While you didn't realize it, the National Anthem does end with "Gentlemen Start Your Engines!"
seawolfe		#9	[-]
Posts: 411 (06/23/09 01:36 PM) Veteran Member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Bumping this after being away from this site for umpteen years. Because I'm very interested in this for my 2001 Frontier XE V6 2WD 5spd crew cab. I want better highway MPG! Has anyone done this? I'm not towing, although I do sometimes carry heavy loads (~ 980 lbs). I guess my main questions are: 1) what is the risk to my baby if I do something like this? 2) Do I have to loose my torqueyness at low gears? 3) Who can do this sort of thing? I'm not a mechanic. Any recommendations? 4) most embarrassing of all: In speaking to a mechanic about this, I tell them I want an "Overdrive Unit"? Carrie aka Seawolfe '01 CC 5 spd Solar XE
Mathster		#10	[-]
Posts: 4982 (06/25/09 03:06 PM) Crazy Member Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	1. you void the factory warranty on the rear differential. obviously, the factory isn't gonna warranty aftermarket parts and work. 2. changing your rear differential will effect the drive ratio of all gears. depending on how much you change, will effect the change in "torqueyness". 3. I would start by talking to a reputable offroad shop. this is usually one of the first things you do after larger tires. 4. Depends on what your actually wanting. A different set of gears in the rear end to give you overall a different ratio? there is such a thing as an overdrive that attaches to the transmission similar to a transfer case that will give you one more final gear and not effect the existing gears. These are usually done on heavier tow rig trucks (3/4 ton, 1 ton, and heavier) so they are very heavy duty units. this may cause too much rotating mass for you to see any benefit. Also, the truck will be operating at a lower RPM range and may not be at near the peak torque curve to realize any benefit. My post above, at 80 mph, the engine runs more efficient than at 55 mph, the improvement is significant enough to overcome the additional drag from the additional speed. While you didn't realize it, the National Anthem does end with "Gentlemen Start Your Engines!"

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Rear diff gear ratios and mileage?

Rear diff gear ratios and mileage?

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