What tuner to buy?

DiabloBlanco

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Hey all! Just installed Rubicon wheels and tires on my 2020 Sport S. Now my mpg has dropped a good bit and my speedometer is 1-2 mph off according to a GPS speedometer app (tested before installing the tires and it matched up). I was wondering if I could get some pointers here. I've heard of people using a tuner to adjust the speedometer and tire size, but not sure which one I should get. Just the Tazer JL mini? I've also heard of people getting a Bluetooth ODB II reader in with a bypass cable and using an app called JScan on their phone to adjust stuff. What do you guys suggest? And will it affect my gas mileage at all when I adjust this stuff or is it just part of getting the bigger tires? I know they're not that much bigger than stock Sport S tires...should it have affected it that much? I'm talking 4-6mpg. Been trying to drive like a grandma even more since installing the wheels/tires and it hasn't helped. Thanks in advance for any help!





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DCBlake

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I use the jl tazer and yes the tires will change mpg. What size tire did you go too? Did you do a lift And if so how high? Are you using the mpg monitor on dash or calculating based on miles driven divided by gal used to fill up?

once you recalibrate using a tazer, superchips flashcal, etc. it will help establish a new baseline as your Jeeps computer will know all of the correct settings. Also if you went to 37’s you may need to look into doing rear gearing of diff.

Now both of the products I mentioned do most of the same things but I just preferred the tazer products as I also used their cable products to install a front camera plus several other products. it helped me add in led lighting, mopar aux switches, etc without having to pay dealer extra fees to reflash computer. As an example to flash computer to add aux switches they wanted $175 so that was almost the cost right there. Just search the forum for each product as there’s a fairly large amount of info on the tazer and several on superchips.

Now if your into doing full tuning I would also search the forum for those topics as others have tried this as well but this is something I haven’t looked into as my rubicon is the 2.0 turbo and I just don’t want to mess with those settings.
 
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DiabloBlanco

DiabloBlanco

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Thanks for the info! I went with stock Rubicon wheels and tires, so 285/70R17. No lift or anything like that yet.
 

DCBlake

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Thanks for the info! I went with stock Rubicon wheels and tires, so 285/70R17. No lift or anything like that yet.
so I will say i get anywhere from 18 - 21 mpg with the 2.0 turbo on my Rubicon depending on driving conditions. In your case you did step up quite a bit if you had the 245 75 17 to start so a big drop in mpg isn‘t surprising. I mean when they do all of those epa estimates they use the smaller tires. so yeah I would get something to recalibrate the computer to know what size tire you have now.
 
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Rhinebeck01

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Hey all! Just installed Rubicon wheels and tires on my 2020 Sport S. Now my mpg has dropped a good bit and my speedometer is 1-2 mph off according to a GPS speedometer app (tested before installing the tires and it matched up). I was wondering if I could get some pointers here. I've heard of people using a tuner to adjust the speedometer and tire size, but not sure which one I should get. Just the Tazer JL mini? I've also heard of people getting a Bluetooth ODB II reader in with a bypass cable and using an app called JScan on their phone to adjust stuff. What do you guys suggest? And will it affect my gas mileage at all when I adjust this stuff or is it just part of getting the bigger tires? I know they're not that much bigger than stock Sport S tires...should it have affected it that much? I'm talking 4-6mpg. Been trying to drive like a grandma even more since installing the wheels/tires and it hasn't helped. Thanks in advance for any help!
@DiabloBlanco Forget the idea that you are going to correct the speedo with a programmer and then see your mpg go back to where it was before the bigger tires.. That is not going to happen!

Would be good to get the speedo programmed as that speedo being off affects your shift points if you have an automatic.

Forget paying the dealer to reprogram the speedo. Wasted $.

Just buy a Tazer JL Mini and easily program the speedo and more with the programmer (it's not a tuner)...You can also defeat ESS with the Tazer JL Mini.

WHEN, in the future you sell your JL, you can easily unmarry the Tazer JL Mini and sell it, thus recooping much of what you paid for the Tazer JL Mini.

You mentioned JScan/OBDll reader.... well, doable but to me that route is still kind of a crap shoot.... in it's infancy phase in regard to the JL. No, ESS defeat with it either... not yet.

The Tazer JL has been around for well over 2 years now and there is lots of hand holding here on the forum, in regard to the Tazer JL. Ask questions here, etc. and you will not get into to many headaches trying to sort usage out.
 

ChaosJeep

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I have a 2.0 Sahara and went from stock tire size to 35s 285/75/18. I bought the jl tazer mini light. Changing the tire size and tpms setting was my main reason for buying the tazer. Also the auto stop/start memory feature is a plus too.
 

Obi.Wan.Shawnobi

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Hey all! Just installed Rubicon wheels and tires on my 2020 Sport S. Now my mpg has dropped a good bit and my speedometer is 1-2 mph off according to a GPS speedometer app (tested before installing the tires and it matched up). I was wondering if I could get some pointers here. I've heard of people using a tuner to adjust the speedometer and tire size, but not sure which one I should get. Just the Tazer JL mini? I've also heard of people getting a Bluetooth ODB II reader in with a bypass cable and using an app called JScan on their phone to adjust stuff. What do you guys suggest? And will it affect my gas mileage at all when I adjust this stuff or is it just part of getting the bigger tires? I know they're not that much bigger than stock Sport S tires...should it have affected it that much? I'm talking 4-6mpg. Been trying to drive like a grandma even more since installing the wheels/tires and it hasn't helped. Thanks in advance for any help!
so yor 2020 does not have etorque? (i dont think any of them do). You wont really see any MPG difference but if you had the etorque, it would compensate off the line for the "added weight".

The added weight is nominal and another thing to consider is rotational mass. Neither of these things really make a difference between your two tires. Just recalibrate to the correct tire size. I doubt you will even see a 1 mpg difference.
 

comatzd

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I have a 2.0 Sahara and went from stock tire size to 35s 285/75/18. I bought the jl tazer mini light. Changing the tire size and tpms setting was my main reason for buying the tazer. Also the auto stop/start memory feature is a plus too.
I believe 285's are generally considered a 33", not a 35". You have to jump to a 315 for a 35", most of those are between 34-35.
 

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