Improving loss of mpg's

[boehml]

It's interesting that you would use the terms "tough guy" and "manhood" to deride me. But that speaks more about you than anyone else.

The fact that you had to respond to MTG shows your acceptance of the above. If you can accept the fact that you're not a "tough guy" and your "manhood" is not in question, you would just leave it be...

I can be a dick sometimes ... sometimes without even trying. I apologize, I might have been trying.

I think we can all appreciate your wisdom, as I do. However, there is no reason to act like a child in what is intended to be a community. We're all on the same team..

Either way, I appreciate the tip on the flash cal, I did not know you could upgrade down the road. I will have to try this out.

 

[Crucial]

No, I was not. The physics involved do not permit a power gain by way of recalculating tire size. In this case the tire is effectively a lever. Increasing tire size is effective moving the fulcrum in relation to the lever such as to decrease mechanical advantage.

And actually, rpm and throttle position are the primary drivers of shift points. Speed has very little, if anything, to do with it. Sometimes it's better to just listen rather than insulting someone because you disagree.

Also, the NAG1 transmission runs off of a separate ECU. It is not accessible from the OBDI-II port - nor has it been successfully hacked by any of the usual suspects.

By all means, correct me if I'm wrong. But please back it up with facts.

most of the programing i have done of different vehicles, i'd say most are based on throttle position vs mph. but i have not programmed anything jeep/chrysler so may be wrong

 

[MedixJK]

So along the thread ive lost sight of my original question...buying the programmer will improve mpgs and help correct my shift points, true or false?

 

[MTG]

It's interesting that you would use the terms "tough guy" and "manhood" to deride me. But that speaks more about you than anyone else.

Hahaha! Exactly the self-righteous response I expected. But since you're such a smart guy I'll just leave this here...

 

[wayoflife]

So along the thread ive lost sight of my original question...buying the programmer will improve mpgs and help correct my shift points, true or false?

Correctly calibrating your speedometer will give you a more accurate reading as to what kind of MPG you are really getting. It will also correct your shift points and this will lead to better MPG as well. It will NOT give you more MPG than you should have already been seeing. Does that make sense?

 

[wayoflife]

I don't believe calibrating the speedo for larger tires will do anything like restoring shift points. At least not for 2012+. It didn't do anything for mine.

Well, you can believe whatever it is you want to believe. :yup:

Shift points are rpm AND speed based. So how could properly correcting your speedo for larger tires not restore shift points? Where you expecting some sort of power gain?

Yup. This is especially true on a 2012+. Try installing a significantly higher gear ratio and bigger tires and see how much your Jeep wants to move. Fact of the matter is, failure to calibrate your speedo on a 2012+ with this setup will put your Jeep into limp mode and all you can do is drive around in 2nd gear. Ask me how I know :crazyeyes:

What do you guys think about the superchip traildash?

They're nice and have a lot of fun functions. I just wish it had a GPS built into it.

 

[NFRs2000NYC]

So being new to this jeep thing, im gonna throw this out there because my jku is my DD. 2012 jkus w 3.21. I went from my jeep saying i was getting 18ish mpg avg, to now 12-13 mpg avg. I did a 2.5" coil lift and put 295/70r17 mxts on factory wheels with spacers. I havent recalibrated anything yet but looking at a superchips unit to get back a lil mileage. Will that help? Any other ideas? Im currently tracking the milage manually but havent refueled yet.

The 3.21s are killing you. I would definitely program your tire size to get back a little bit, but you will get the most mpg back when/if you regear to take the load off the motor and make it easier to turn the tires. I had the same problem with my 2012 Sahara with 3.21s on 33s. I have a 2014 Rubi on 35s now, with 4.10s, and get better gas mileage. The 3.21s are just terrible gears for the jeep.

 

[wayoflife]

No, I was not. The physics involved do not permit a power gain by way of recalculating tire size. In this case the tire is effectively a lever. Increasing tire size is effective moving the fulcrum in relation to the lever such as to decrease mechanical advantage.

And actually, rpm and throttle position are the primary drivers of shift points. Speed has very little, if anything, to do with it. Sometimes it's better to just listen rather than insulting someone because you disagree.

Also, the NAG1 transmission runs off of a separate ECU. It is not accessible from the OBDI-II port - nor has it been successfully hacked by any of the usual suspects.

By all means, correct me if I'm wrong. But please back it up with facts.

The ECU you are thinking of is actually a part of the new transfer case, not the transmission. This is in part why you cannot run a Rubicon transfer case that came off a manual on an automatic even if it came off a 2012. Of course, you can run a transfer case that came off a manual on ANY 2007-15 JK. That's because shift points on a manual are determined by the person driving it. As mentioned before, failure to calibrate your speedometer especially on a 2012-up will put your Jeep into limp mode. Physics has nothing to do with it.

I'm not an engineer but I have studied physics in both the academic environment as well as on my own, more so as it relates to helicopters and other flying things. Also rebuilt my first engine at roughly age 10 and have rebuilt many others since then. This doesn't make me an authority on anything but I know what I know. For instance, I know that TC lockup can only occur once the disparity between crankshaft and driveshaft, through whatever system of gears and hydraulic clutches, is effectively reduced to zero. A TC is essentially just a clutch that facilitates this process. They aren't what I'd describe as adjustable.

Well, I once stayed at a Holiday Inn Express :yup:

I can be a dick sometimes ... sometimes without even trying. I apologize, I might have been trying. I might also be a bit jaded. I'll work on that. I don't know Prime8 but my guess is this person might on occasion be just as arrogant, opinionated and condescending as me. I pity da foo!

Nah, Prime8 was just an insecure kid who shot off his mouth and tried to use big words in an effort to make himself look more important. I do pity him though.

 

[JeepFan]

Well after reading all this I'm totally confused..:crazyeyes: How exactly does lifting a Jeep, putting on bigger tires, re-gearing and re-calibrating the speedo equal improved gas mileage? Do you mean improve as in better than 11 MPG? LOL! Woohoo!

I agree, the re-cal will definitely correct the shift points. It will also accurately confirm that your mileage will suck after doing all of the above. :yup:

 

[Benito]

Do you mean improve as in better than 11 MPG? LOL! Woohoo!

yes, i believe this is what they mean.

 

[wayoflife]

... It will also accurately confirm that your mileage will suck after doing all of the above. :yup:

:cheesy: simply said but oh so right! :crazyeyes:

 

[MedixJK]

Correctly calibrating your speedometer will give you a more accurate reading as to what kind of MPG you are really getting. It will also correct your shift points and this will lead to better MPG as well. It will NOT give you more MPG than you should have already been seeing. Does that make sense?

Yea absolutely. Thanks a ton

 

[MedixJK]

Yea im not looking to gain mpgs, im looking to make my speedo correct and improve the way my motor and transmission are working right now. Its basically all over the place and is never sure exactly when it should be shifting. I.e., staying in gear too long, or up shifting too soon

 

[littlered_jk]

Question about fuel economy though. I filled up after installing tune. Reset both the traildash fuel economy gauge and the jeep evic. Right now the Superchips is reporting 2mpg better than the jeep evic. I set the correct tire size in and the speedometer is correct with my phone gps. So my question is which is correct. Traildash or EVIC[/QUOTE

 

[MKJK]

I have the same problem, traildash says 20mpg, jeep says 15.9L/100. So 15ish mpg....

 

[jeeeep]

do the calculations manually to find out your true mpg's

 

[Saharacon]

Easy get your self a superchip and reprogram your ecu for the large tires. I gained 3 MPG back when I did this

 

[Saharacon]

Also remember the MPG on the computer is inaccurate