Help please...lots of questions!

Joe41791 · 05-27-2012, 01:19 AM

I had 2.93 stock gears on 35s and averaged 11mpgs city's/highway. Now I have 410 gears on 35s and a got a bdgt to help out. my trip says I'm gettin 8.8 mpg when calculated at the pump..the bdgt says I'm getting 10...idk what's going on anymore! with my 410 gears can anyone tell me how far off my speedometer is? I bought the bdgt thinking it'd recalibrate my speedometer but apparently there's not a program for titans yet

I need to figure out what mpgs I'm really getting and also how fast I'm really going. What should I be averaging per gallon? Keep in mind I have been driving like a granny to keep optimal fuel economy. Also Does anyone know how to adjust the fuel display accordingly on my truck with 35s? And what is the best program tune to use on the bdgt? I know it's alot of questions but this is buggin the hell outta me!

Joe41791 · 05-27-2012, 02:17 AM

Anything helps! If not any answers than any suggestions as to what I need to do to improve mugs better than 8?? Haha, my current mods are listed below, maybe there's something im missing that I can do...besides buying a 4cylinder! I have one already but when I take my truck to the lake it'd be nice to get decent mileage so I can spend more on beer an less on gas!

cayers1122 · 05-27-2012, 06:01 AM

That's crazy bad mpg your getting. I have an 05 4wd with the level kit and headers and cat back and intake and uprev. I am running 325/60/18 tires that are about 34" tall and really wide and I average 17mpg on the hwy at 70-80mph. I calculate my mileage using my gps trip odometer to make sure it's accurate. I also do not have the big tow gears so changing to a lower gear may have hindered your mpg. Not sure on that one.

**Carbeaux** · 05-27-2012, 06:23 AM

For accuracy, you'll probably have to figure out your difference in miles traveled with the new gears and tires yourself. Get on an interstate with mile markers and drive about 10 miles (by mile markers) and see what mileage your odo measures. Use a GPS if you have that. Then calculate that difference in when you manually figure your mpg at the pump.

SUBTITAN · 05-27-2012, 07:01 AM

I would think your MPG's would drop some with the new gears, has your RPM's increased since the gear change. Good recommendations for calculating speed until correcting speedometer.

**nightowl** · 05-27-2012, 07:46 AM

Im 2wd with stock tires and my bdgt is always 1mpg lower than my calculations.

DRTYAZN · 05-27-2012, 11:22 AM

3:36 w/ 35" tires... when I had a BDGT, I used my GPS to confirm speed and BDGT was matched with the dash, but adjusted +4%, it was in synch with my GPS... as for MPG, I'm averaging 10mpg city and 15mpg highway...

Joe41791 · 05-27-2012, 06:45 PM

Ok thank you everyone, I think my solution is trade someone my 4.10 gears and go 3.36s or 3.73s. Anyone need some 410s??

**Scan999** · 05-27-2012, 07:01 PM

Quote:

Originally Posted by Joe41791

I had 2.93 stock gears on 35s and averaged 11mpgs city's/highway. Now I have 410 gears on 35s and a got a bdgt to help out. my trip says I'm gettin 8.8 mpg when calculated at the pump..the bdgt says I'm getting 10...idk what's going on anymore! with my 410 gears can anyone tell me how far off my speedometer is?

Sounds perfectly normal. You had highway gears before and when you added 35" tires the truck was sluggish off the line and your MPG was 11. Now you have rock crawling gears and your MPG is way down since the engine is working harder. I bet the truck is a rocket off the line now. If MPG is really an issue you might want to go to stock 3.36 gears. It might be a better balance of city and highway and your MPG's should return to where you were before. I haven't seen a tuner make any real difference in MPG unless you put a higher octane gas which cost more and defeats the purpose of saving money.

Joe41791 · 05-27-2012, 07:33 PM

Quote:

Originally Posted by Scan999

Sounds perfectly normal. You had highway gears before and when you added 35" tires the truck was sluggish off the line and your MPG was 11. Now you have rock crawling gears and your MPG is way down since the engine is working harder. I bet the truck is a rocket off the line now. If MPG is really an issue you might want to go to stock 3.36 gears. It might be a better balance of city and highway and your MPG's should return to where you were before. I haven't seen a tuner make any real difference in MPG unless you put a higher octane gas which cost more and defeats the purpose of saving money.

My truck came stock with 2.94s. The 3.36 gears must be off of a big tow huh? And even if I run 91 or fuel saver with low acceleration my MPGS SUCK!and yea0-60 they can't catch me! Haha.if I can get 13 I'll be a happy camper, whats the likelihood of that though? Keep in mind I refuse to part with my 35s! Haha, I'll pay the gas bill before I do that

Joe41791 · 05-27-2012, 07:39 PM

Quote:

Originally Posted by SUBTITAN

I would think your MPG's would drop some with the new gears, has your RPM's increased since the gear change. Good recommendations for calculating speed until correcting speedometer.

Oh yea the rpms jump up with the 35s and 4.10s. On the bright side My trucks way quicker and i got insane power! Haha

**Scan999** · 05-28-2012, 06:22 AM

Quote:

Originally Posted by Joe41791

My truck came stock with 2.94s. The 3.36 gears must be off of a big tow huh? And even if I run 91 or fuel saver with low acceleration my MPGS SUCK!and yea0-60 they can't catch me! Haha.if I can get 13 I'll be a happy camper, whats the likelihood of that though? Keep in mind I refuse to part with my 35s! Haha, I'll pay the gas bill before I do that

I get between 12.2 and 13.2 MPG with 90% city and 10% highway and that is with stock size 33" tires and big tow 3.36 gears. I'm not sure you will get 13 with 35" tires but I am pretty sure you'll get better than the 8.8 you are getting now.

crazynelsons · 05-28-2012, 10:17 AM

I have the 4.10's on 285/70/R17
Superchip on 91oct and 2* advance
Getting 13.6 mpg avg.
I did not have to calibrate the speedo (matched it with 2 GPS')
For some reason it self calibrated.
Hypertech does sell a speedo calibrator for the Titans. But not sure why my truck did'nt need it.

Joe41791 · 05-28-2012, 10:02 PM

Quote:

Originally Posted by crazynelsons

I have the 4.10's on 285/70/R17
Superchip on 91oct and 2* advance
Getting 13.6 mpg avg.
I did not have to calibrate the speedo (matched it with 2 GPS')
For some reason it self calibrated.
Hypertech does sell a speedo calibrator for the Titans. But not sure why my truck did'nt need it.

Well I'd be happy with 13.6 but what size are your tires? I don't now exactly how big 285s are... I have 35s with the 4.10s and I'm only gettin 8.8!! I can't have that! And I'm on the bully dog on 91octane with a 2* advance also! And my speedo may be correct already, idk I don't have a gos to match it to

**Scan999** · 05-29-2012, 12:07 AM

I think there is more to the gearing with the Titan than just simply swapping out the rear end axle ratio. Nissan played with the transmission gearing to get the 2.94 to "feel" like a 3.73 and the 3.36 to 'feel" like 4.10. When you actually put 4:10 gears in your truck the engine works very hard. Larger diameter tires help compensate but maybe not enough.
2.94 stock gearing:
1st: 3.827 x 2.94 = 11.174:1
2nd: 2.368 x 2.94 = 6.961:1
3rd: 1.520 x 2.94 = 4.468:1
4th: 1.000 x 2.94 = 2.94:1
5th: 0.834 x 2.94 = 2.451:1
4.10 gearing:
1st: 3.827 x 4.10 = 15.690:1
2nd: 2.368 x 4.10 = 9.708:1
3rd: 1.520 x 4.10 = 6.232:1
4th: 1.000 x 4.10 = 4.10:1
5th: 0.834 x 4.10 = 3.419:1