Understanding the ECU 101..:or how im getting over 20mpg on 37’s

[C0mm0n773]

i dont follow the question.....if you want the best you can get while changing no parts, driving habits is all you can do. If by stock you mean no lift/tires, then start with tuning and better fuel, and go from there. Id be willing to bet that a stock Sahara that does this will get damn near 30mpg on the highway at sea level.

Yea I mean stock as in the only upgrade I’ve done was receive a random duck which was placed on my door handle. Right now all I do is focus on the MPG meter whatever it’s called. As far as tuning goes how do I go about that? How much is it? Who do I contact?

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[Kurt0]

Yea I mean stock as in the only upgrade I’ve done was receive a random duck which was placed on my door handle. Right now all I do is focus on the MPG meter whatever it’s called. As far as tuning goes how do I go about that? How much is it? Who do I
contact?

only tunes im aware of currently are the Superchips Pulsar and the Livernois tuning. Price varies with options; but plan on $5-800

 

[WilhelmSR]

Just joking around. Great information. Thank you for putting this together

 

[Kurt0]

Just joking around. Great information. Thank you for putting this together

if someone wants to fund mw getting a class and a better camera; im all in.

Maybe i could start an OnlyFans page and get paid that way??

 

[WilhelmSR]

Maybe i could start an OnlyFans page and get paid that way??

 

[Gorilla57]

if someone wants to fund mw getting a class and a better camera; im all in.

Maybe i could start an OnlyFans page and get paid that way??

See..... knew I wasn’t the only one.....

 

[Kevin Mojito]

No mods to engine, intake, exhaust or tune. Mods are 35's lift, winch,.... I'm at just over 5200 lbs. without me. Always get 17-18 mpg's. Just last 2 tanks I have started using the manual mode shifting. I let the auto mode to get up to speed ( whatever the limits is ) then push to manual mode. I have been running no more then 1500 rpms in manual mode. Doing this has pushed my mpg's for the 2 tanks to 20 - 20.5 mpg's.

 

[wchevron]

Very informative. Can g

ive had some issues with the Pulsar. Not as bad as what people previously dealt with, and it took some doing to get engagement from Superchips, and they say its covid restrictions in cali. I dont live in cali, but know its been restrictive, they're working with me now to get the new unit once its built and hopefully thats the end of it. I think the livernois would be a great and well made tune, I just personally prefer the pulsar form factor, as mentioned.

It's pretty tough to compete with the efficiency of a diesel, especially if you tune it well...especially if you're loaded down with weight. all that said, yes, the factory leaves a ton on the table with these.

this is the specific filter: https://afepower.com/afe-power-73-80280-magnum-flow-pro-guard-7-air-filter. parts for the pulsar, mopar intake, and AWE exhaust should all be self explanatory with a JL related field search.

Also keep in mind I dont drive that fast. My runs are always with prodigious use of cruise control, no more than 5mph over the speed limit, and a maximum speed of 70. We can't tune out the aerodynamics of the brick. lol. I also think these trucks are over geared. I havent done a test with the 4.88's yet, and wont for a bit until they are worn in.

Hope that helps.

Very informative. This is all new to me so sorry if the questions are dumb. I understand the basic concepts you layed out. With a Rubicon with stock wheels, is the pulsar still needed for tuning or is it primarily due to the 37's you are running to get correct tire sizing.
Also is the AWE exhaust required or can you get some MPG gains with the larger intake and filter? I'm assuming the exhaust is some factor in the equation just not sure how much.

 

[Kurt0]

No mods to engine, intake, exhaust or tune. Mods are 35's lift, winch,.... I'm at just over 5200 lbs. without me. Always get 17-18 mpg's. Just last 2 tanks I have started using the manual mode shifting. I let the auto mode to get up to speed ( whatever the limits is ) then push to manual mode. I have been running no more then 1500 rpms in manual mode. Doing this has pushed my mpg's for the 2 tanks to 20 - 20.5 mpg's.

35’s are not 37’s.

could be you have a previous ecu file pre misfire issue; you drive even more conservatively than I do; where you live isnt as hilly as my route.

how did you change tire size in the ecu once you changed?

the primary point is that your motor doesnt have the power to overcome 8th gear overdrive on those 35’s. Tuning helps.

 

[Kurt0]

Very informative. Can g


Very informative. This is all new to me so sorry if the questions are dumb. I understand the basic concepts you layed out. With a Rubicon with stock wheels, is the pulsar still needed for tuning or is it primarily due to the 37's you are running to get correct tire sizing.
Also is the AWE exhaust required or can you get some MPG gains with the larger intake and filter? I'm assuming the exhaust is some factor in the equation just not sure how much.

short version; everything makes a difference. I ran the pulsar to improve ecu tuning as well as tire correction.

its hard to say what made bigger difference between intake or exhaust. I would *GUESS* exhaust makes a bigger difference When stock; and it would be a toss up between intake or exhaust when tuned.

 

[Bingman]

This is all very informative, thank you for sharing. Question for you. Are you familiar at all with the “spark knock” issue with the 3.6l wranglers? Not sure if it’s a thing in the gladiators or not. I’ve got a 2020 JLU 3.6 auto, and get spark knock in the summer time when, for example, I’m taking a turn at a low rpm and apply light throttle. If I give it enough throttle to downshift, it won’t happen. It also happens going up hills on the road and on the trails if throttle is applied but transmission doesn’t down shift. I’ve tried running 93, but that doesn’t seem to make much difference in my case, although others claim they’ve had luck with it. A while back I asked livernois. If their tune would help do away with this, and they said it would. Any idea if the pulsar tune would help out with this?

 

[Kurt0]

This is all very informative, thank you for sharing. Question for you. Are you familiar at all with the “spark knock” issue with the 3.6l wranglers? Not sure if it’s a thing in the gladiators or not. I’ve got a 2020 JLU 3.6 auto, and get spark knock in the summer time when, for example, I’m taking a turn at a low rpm and apply light throttle. If I give it enough throttle to downshift, it won’t happen. It also happens going up hills on the road and on the trails if throttle is applied but transmission doesn’t down shift. I’ve tried running 93, but that doesn’t seem to make much difference in my case, although others claim they’ve had luck with it. A while back I asked livernois. If their tune would help do away with this, and they said it would. Any idea if the pulsar tune would help out with this?

i wouldnt recommend trying to use a pulsar to correct that issue, because its modifying signals vice remapping the ecu. It COULD fix it, and in theory SHOULD, but you wouldnt know until you sank the cash.

my advice would be to either remap with livernois; or get the TSB reflash done at the dealer and then add Pulsar. If you add the pulsar, be mentally prepared to have to get the TSB reflash done regardless.

 

[Kevin Mojito]

35’s are not 37’s.

could be you have a previous ecu file pre misfire issue; you drive even more conservatively than I do; where you live isnt as hilly as my route.

how did you change tire size in the ecu once you changed?

the primary point is that your motor doesnt have the power to overcome 8th gear overdrive on those 35’s. Tuning helps.

Bought it new. Has 8000 miles on it now. Have every tank/mpg fill record. It has only gotten 17-18 mpg's.. It has a lift with crap on it now ( since 3500 miles ) still gets 17-18 mpg's.
I use a tazer mini to correct the speedo. Still 17-18 mpg's.
Started with the last 2 fill up's with using the manual mode shifter, once at speed pushing it to stay 1500rpm and has boosted the mpg's 20-20.5 mpg's. Nothing else was done. I still drive the same way, until I'm up to speed then manual shift ( hold the trans in 7th or 8th .)
I live with nothing but hilly area. from 400 feet to 3,200 feet. my property run's 80 feet in height change.....

 

[Bingman]

i wouldnt recommend trying to use a pulsar to correct that issue, because its modifying signals vice remapping the ecu. It COULD fix it, and in theory SHOULD, but you wouldnt know until you sank the cash.

my advice would be to either remap with livernois; or get the TSB reflash done at the dealer and then add Pulsar. If you add the pulsar, be mentally prepared to have to get the TSB reflash done regardless.

Thanks, I appreciate the help. I tried getting the TSB done back in October but go figure, they “couldn’t hear it.” Even though all it was a pcm reflash. Just called a different dealer and they said they’d do it even though it doesn’t make the noise in the winter time. Thanks for getting me on track! Much appreciated.

 

[Kurt0]

just finished a mostly interstate and highway (with stoplights) route i frequently drive.

3” lift, 37’s, 4.88’s, 3 occupants, 400lbs of cargo from northern MD to central VA.

203.7miles. Displayed MPG 19.7; hand calc was 20.6.

7th was frequently used on hills, but nothing i to 6th i can recall that wasnt speed related. So, i expect it to go to 7th time to time for hills to maximize 8th cruise, as it It still overdrive. The trans never felt “busy” or “undecided” about its gear. I found the drive perfect.

given the conditions, the 4.88 gears accounted for passengers, 3” of lift/airdrag, and 400lbs of cargo while losing less than .5 MPG along that same route when compared to stock height/37’s/stock gears/no cargo. Thats within “the noise“.

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