JL Package Protected for 35s

[JLWF Dealer Guy]

Internally, the service department can adjust current vehicles to larger tire sizes. Its a program not available to users and not in the vehicles settings. So, what they are doing is allowing them to adjust that setting if someone puts on 35" tires. Not 100% but it looks like anything bigger will need the addition of a procal or similar aftermarket unit as we have done before.

Sponsored

 

[DanW]

I'm curious how this would work with sufficient accuracy. GPS is great, but often off by a mile and hour or so. It may be accurate enough in most eyes, but I want it spot-on. I'd love to just measure the tire height and program it in, within a quarter or even an eighth of an inch. Then, it would be a piece of cake. A Pro-Cal works off the actual tire height, with the normal weight of the Jeep on it.

 

[TLife]

GPS is great, but often off by a mile and hour or so. It may be accurate enough in most eyes, but I want it spot-on.

I don’t know the specifics of your situation, but if you’re comparing GPS speed to your speedometer and seeing a difference my money would be on the speedometer being inaccurate.

within a quarter or even a fourth of an inch.

But what about two eighths????

 

[DanW]

But what about two eighths????

Lol! Long day! I meant to say 1/8.

I've used GPS units for many years, as a pilot and in other applications. Very often, they are 1mph off. I've seen this with the same GPS units moved to different vehicles. Sometimes they are right on, but the variance can be caused by a variety of variables in conditions, reception, etc.

I guess 1mph in the grand scheme of things isn't a big deal, but I'm a bit OCD about that kind of stuff. Honestly, that's probably how the JL will do it. I'll probably be happy that it will save me some money.

 

[JimKrrk]

The problem with build-in vehicle GPS is that they use the MPH setting from the tire size setting in the vehicle computer, not the satellite GPS. So if you have larger tires without having the tire size changed it can be way off on the GPS. This is why I used an aftermarket device to change my tire size setting until it matched with my most accurate Garmin unit's mph.

 

[nowandthen]

I don’t know the specifics of your situation, but if you’re comparing GPS speed to your speedometer and seeing a difference my money would be on the speedometer being inaccurate.



But what about two eighths????

The AEV pro-cal uses diameters to the nearest 1/4". That is close enough. If you want 1/8" are you really going to remeasure your tire every few months? I know I haven't remeasured my tires after more than a year of use (I should check them ) I do a 5 tire rotation, so tire wear will be slightly different between tires, not to mention how tires wear depending on many factors.

I think you want to measure the diameter of the tire, (say font to back horizontally, not the height of the tire with weight "deforming" the tire. It's a minor difference if your tires are adequately inflated, but if you think about it, the tire has a circumference, it doesn't matter that part of it's travel is somewhat flat. it still has a specific number of inches to turn to reach one revolution.

 

[BillyHW]

In theory it shouldn't be that hard to do. The computer could monitor the internal GPS for true distance travelled and compare that to the number of wheel rotations, calculate the discrepancy from stock, from which it could calculate the new tire size and then adjust everything in the computer accordingly that would need to be adjusted, like speedometer, odometer, mpg, (shift points?) etc.

With something like that you could change back and forth between any size tires and everything would automatically adjust itself every time. You could have a set of 31s or 33s for daily commuting and another set of 35s or 37s for off-roading and just switch them when you wanted to without any hassle.

But do I believe the FCA engineers actually came up with something this brilliant? Yeah, sure.

Sponsored