MPG stinks after rearend replacement

titansurveyor · 07-03-2004, 09:49 AM

Ever since my rearend was replaced in my May my MPG has gone to crap. I was averaging about 13.5 to 14 before the replacement, now I'm only getting 10.5 or 11 at best. This is all the same type of driving. Back and forth to work which is 10 miles away, with some freeway.

Also I can't peel out from a dead stop anymore. Yes the VDC is off. My plan is to take it back to the dealership, but wanted to get your opinions first. The truck now had 3900 miles on it.

Thanks

37L1 · 07-03-2004, 10:01 AM

Take it back for sure.

If you're curious, you might want to check what's happening in the diff yourself. All it would cost is some gear oil and time.

Maybe it's not even the differential. It might be something else, what with the luck you've been having.

Good luck, it's about time you got some.

37L1

PHOEBISIS · 07-03-2004, 11:35 AM

titansurveyor,this might not be much help,but the ECU might have a learning curve built in,or even some sort of "governor" that slows it down,or shifts softer after the battery has been D/C for a period of time.On the Honda Pilots we lose 2-3 mpg for about 300-600 miles,one or 2 tanks,after the battery has been disconnected.The "explanation" is that the vehicle reverts back to a very rich, safe but soft shifting mode,then slowly selects maps for your driving???I know this sounds like pure BS,but this is the explanation given by Honda "experts" on the Pilot forum???
If you are into conspiracy theories,maybe the Nissan techs put it in a "sissy mode"-that will "wear off" after the differential replacement.More likely this is some sort of built in "breakin mode" that always kicks in after electrical power is lost.
Do you still turn~1750 RPMS at 60mph?Check just to make sure they didn't put the wrong gears in-1550 would indicate the 2.94.Luck,Charlie

PA Titan · 07-03-2004, 11:51 AM

Maybe they screwed up and put in a ford rear end. That would also explain 11 mpg.

Actually I would wait because my Titan was only getting 11 mpg when I bought it but the mpg is about 15 now. Its like the computer or something needed to burn in.

Xterra · 07-04-2004, 10:09 AM

I love the Titan and my X, just can't figure out why they get worse gas mileage than GM or Ford? My friend gets 18 MPG with his Silverado.

bigmd10 · 07-04-2004, 11:43 AM

I just hit 5000 miles and the last two tanks have been at 12 mpg or worse, all tanks previous to this were at least 13.8 or higher. No change in driving patterns ethier, What gives?

BossHogg · 07-04-2004, 10:53 PM

Interesting. I am getting around 13 in the city and 18 on the highway. Averages to around 15.5mpg at the pump. I keep hearing guys saying they get wide differences, but mine only has 1000 miles on it. I am light footed, hell, I even let a Geo Metro beat me off the line the other day. Are you guys the first to the next light everytime or something?

DallasTitan · 07-04-2004, 10:59 PM

BossHogg,

I've tried it your way and the jack rabbit way. It seems the results are almost identical. The avg. MPG still stuck at 12-14!?

beano · 07-04-2004, 11:09 PM

Quote:

Originally Posted by PHOEBISIS

titansurveyor,this might not be much help,but the ECU might have a learning curve built in,or even some sort of "governor" that slows it down,or shifts softer after the battery has been D/C for a period of time.On the Honda Pilots we lose 2-3 mpg for about 300-600 miles,one or 2 tanks,after the battery has been disconnected.The "explanation" is that the vehicle reverts back to a very rich, safe but soft shifting mode,then slowly selects maps for your driving???I know this sounds like pure BS,but this is the explanation given by Honda "experts" on the Pilot forum???
If you are into conspiracy theories,maybe the Nissan techs put it in a "sissy mode"-that will "wear off" after the differential replacement.More likely this is some sort of built in "breakin mode" that always kicks in after electrical power is lost.
Do you still turn~1750 RPMS at 60mph?Check just to make sure they didn't put the wrong gears in-1550 would indicate the 2.94.Luck,Charlie

How could they put in 2.94 gears in if he has 4 wheel drive? That would tear the transfercase out when he locked in 4 wheel drive. I would think the mechanics are smarter than that.

titansurveyor · 07-06-2004, 04:01 PM

Well the stealership said the mileage was normal and true mpg won't show up until 5000 or 7000 miles. They can't explain the loss of power they said there isn't any? Maybe I'm just used to it now. Still can't peel out from a stop though. My buddy gets better mileage with his Super duty V10 then I do. Kind of pisses me off. Oh well.

Oh yeah they found out my windshield leaks and now they have to replace it. Won't have it for 2 days! Does it ever end?

37L1 · 07-06-2004, 07:58 PM

"if it wasn't for bad luck, I wouldn't have no luck at all."

"Good grief, Charlie Brown!"

pciley · 07-06-2004, 08:26 PM

Wow... maybe you can lemon your truck. Just sabotage a few things and get a new one

I have 6900 miles, not a single problem yet past a squeak in the guages/dash that I fixed myself. I did have to top off the rear diff though...
What did you do to diserve this bad karma???

avroflyer · 07-06-2004, 09:20 PM

Those lemon laws work! Keep pushing and pushing and eventually you will win so long as you know you have a case that fits the laws of the state you reside in.

On the subject of MPG though, 856 miles now with an average of 15.2 MPG with mixed driving.

StumpZ · 07-07-2004, 07:02 AM

No way a SD V10 gets better gas mileage unless your tank is leaking. I'm not doubting you, I just think your buddy is pulling your leg. The Titan is no miser, but it gets the same gas mileage as my '01 Yukon I traded in.

titansurveyor · 07-07-2004, 08:17 AM

For Lemon Laws here in Cali I think the same item has to break 3 times within a certain amount of time. Although I am not sure about this, guess I will have to do some research on it. I don't know what I did to deserve this. Maybe my buddy is pulling my leg but there are some guys on rv.net claiming better mileage then what I am getting. I know it's a truck and I'm not going to get great mileage.