Driving on larger tires without a tazer, programmer, or tuner

JTCO

Meme King
So, I'm planning on putting some bigger tires on my Gladiator sooner than expected but may have to wait for the Tazer to arrive. Any issues running larger tires for a week or so without it? Will the Jeep go into limp mode or cause any problems? Or should I just wait and do it all at once? I would assume there are some JL or JT owners here that have either done it or attempted it. Thanks.
 

CalSgt

Member
So, I'm planning on putting some bigger tires on my Gladiator sooner than expected but may have to wait for the Tazer to arrive. Any issues running larger tires for a week or so without it? Will the Jeep go into limp mode or cause any problems? Or should I just wait and do it all at once? I would assume there are some JL or JT owners here that have either done it or attempted it. Thanks.

I ran my JL for a few weeks on 37's without a programmer with no real issues to speak of... I do however recommend getting a speedometer app on your phone so you have a good idea of where to adjust for speed. Before I reprogramed with the tazer, when the jeep speedometer read 65 mph I was actually going 72 and at 70 mph I was actually going about 78. Its a miracle I didn't get a ticket, there are stretches of road that have a 65 mph limit that I normally set cruise to 72 on which means I was going about 80.
 

JTCO

Meme King
I ran my JL for a few weeks on 37's without a programmer with no real issues to speak of... I do however recommend getting a speedometer app on your phone so you have a good idea of where to adjust for speed. Before I reprogramed with the tazer, when the jeep speedometer read 65 mph I was actually going 72 and at 70 mph I was actually going about 78. Its a miracle I didn't get a ticket, there are stretches of road that have a 65 mph limit that I normally set cruise to 72 on which means I was going about 80.

Good to hear of no issues. I have a poser flip phone. I work on a computer all day so I have no desire for a smart phone. With that being said, I constantly find myself speeding anyways with this new powertrain even in stock form. It's badass. My other Jeep's speedo is way off anyways so I try to just stay with traffic. I'm just glad to hear there are no real issues with limp mode or anything like that.
 

Like Calsgt I didn’t notice any limp mode or problems. The speedo was off but that’s about it. Only other thing was the slight sluggishness that came with going with 37s, but 4.88s are on the list this year.
 

JTCO

Meme King
Like Calsgt I didn’t notice any limp mode or problems. The speedo was off but that’s about it. Only other thing was the slight sluggishness that came with going with 37s, but 4.88s are on the list this year.

Good to hear. I'll be doing 35s and have 4.10s. I do expect to lose a little power with the bigger tires.
 

ddays v2

Member
Good to hear. I'll be doing 35s and have 4.10s. I do expect to lose a little power with the bigger tires.

I'm running this combo on my Rubicon. You'll be surprised at how little power you lose with it. Other than not shifting into 8th much, I really can't tell much of a difference. I haven't adjusted
my speedo with my Tazer yet but it's only off 3 mph so meh, it's not a priority.
 

JTCO

Meme King
I'm running this combo on my Rubicon. You'll be surprised at how little power you lose with it. Other than not shifting into 8th much, I really can't tell much of a difference. I haven't adjusted
my speedo with my Tazer yet but it's only off 3 mph so meh, it's not a priority.

Hmmmm, that's not bad at all. So no issues at all? You guys have 75 mph highway speed limits out there? I'm wondering if I should even buy the tazer at all then? I probably still will because I want to fix the tpms and the auto start/stop as well.
 

ddays v2

Member
Hmmmm, that's not bad at all. So no issues at all? You guys have 75 mph highway speed limits out there? I'm wondering if I should even buy the tazer at all then? I probably still will because I want to fix the tpms and the auto start/stop as well.

Honestly I haven't had a single issue. We have 70 but 75 is the norm and usually what I drive at. No mountains like you have but we are very hilly here. 8 speed is a dream. I wish my '14 has this Jenner.
I bought my Tazer for all 3 of the reasons you stated above but still haven't used it yet :crazyeyes: The speedo issue really turned out to not be one so I haven't taken the time yet.
 

JTCO

Meme King
We have 70 but 75 is the norm and usually what I drive at. .... The speedo issue really turned out to not be one so I haven't taken the time yet.

At highway speeds with 35s, how far off do you assume your speedo is?
 

ddays v2

Member
At highway speeds with 35s, how far off do you assume your speedo is?

3 mph or so. Possibly 4 closer to 75 mph. I've spot checked it with the speedo on my phone when I use Google Maps for directions. I don't think there's a cop around that's gonna
nab you for that.

Y'know, you really gotta ditch that flip phone! :crazyeyes:
 

JTCO

Meme King
3 mph or so. Possibly 4 closer to 75 mph. I've spot checked it with the speedo on my phone when I use Google Maps for directions. I don't think there's a cop around that's gonna
nab you for that.

Y'know, you really gotta ditch that flip phone! :crazyeyes:

I'll probably end up doing the tazer. I catch myself speeding in this truck all the time as is.
 

YAHAHA

New member
At highway speeds with 35s, how far off do you assume your speedo is?

There are a number of online tire size calculators that will tell you the speed difference on different tire sizes. This is a good example:

https://tiresize.com/calculator/

We’ve been running 35s on our JLUR for 2 years with no noticeable issues.


It's not just a Jeep, it's an amusement park on wheels.
 

JTCO

Meme King
There are a number of online tire size calculators that will tell you the speed difference on different tire sizes. This is a good example:

https://tiresize.com/calculator/

We’ve been running 35s on our JLUR for 2 years with no noticeable issues.


It's not just a Jeep, it's an amusement park on wheels.

Sweet. Thanks. So looks like in town I'll be about 3 mph off but on highway, about 7mph.
 

DavidDJL69

Member
My 2018 JLUR runs stock gears, TR beadlocks, no TPMS, and 37 Nitto Ridge Grapplers. Had the Tazer hooked up for a time but removed it. The differential is about 10% so it’s pretty easy to gauge what I’m going compared to what the speedo is saying.


Sent from my iPhone using JL Wrangler Jeep Forum mobile app
 

JTCO

Meme King
Thanks for all the advice. All is good. Went ahead and got the tires on. No issues at all on the test drive. And the power felt the exact same IMO. Sport S JT with max tow (4.10s) and 315/70R17. I'm going to order a tazer tomorrow just to set it up right.
 

Thanks for all the advice. All is good. Went ahead and got the tires on. No issues at all on the test drive. And the power felt the exact same IMO. Sport S JT with max tow (4.10s) and 315/70R17. I'm going to order a tazer tomorrow just to set it up right.

I’ll tell ya what, the TPMS light alone will make it worth while. I friggin hate staring at that thing all the time. Now that I’m used to it start/stop doesn’t bother me any more. The new procal from AEV doesn’t do TPMS anymore which sucks.
 

JTCO

Meme King
I’ll tell ya what, the TPMS light alone will make it worth while. I friggin hate staring at that thing all the time. Now that I’m used to it start/stop doesn’t bother me any more. The new procal from AEV doesn’t do TPMS anymore which sucks.

Truth.

Which model tires did you buy?

I actually had a set of brand new Goodyear Wrangler Duratracs that I purchased for our JK a couple of months ago. 315/70R17. Yesterday I thought it would be fun to throw the tire/rim on the Gladiator just to see what it would look like and loved it. So today, I bought another set of used 35" tires/wheels on Craigslist and put them on the JK. So the new Duratracs on the JK ended up on the Gladiator. This is our 2nd set of Duratracs. Love them for rain/snow.

DSC06147.jpg
 

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