New member, wwanted to say Hello and I have a few questions for you all.

[atldc9]

Hi all, Just purchased a CPO 2021 Gladiator Overland Diesel wioth 17k. I have had a couple wranglers in the past but made the jump to a truck.

I love the truck so far but I noticed she is riding on Rubicon Wheels and tires. I wondered why she looks just a lil better then a stock overland. So my question is should I do anyting with the larger wheels and tires to prevent issues and is it worth buying a ZAutomotive Tazer to calibrate the speedo for the slightly larger wheels and tires? I saw a post about adding them and I will be honest it kinda got me in the weeds with links to external sites talking about plus sizing, wheel offset ect. I'm just a dumb mountain dweller with a truck.

Second question, It has the Mopar Hard Tonneau Cover, I notice when opened all the way it doesn't have a stop of any kind and sits against the window. Some other brands have a strut or stop how do you safely haul with it fully open and not damage the window?

Also now that I have this baby what accessories would you recommend and any care advice for the Diesel, it's my first time not burning gas?
I'm thinking the Oracle Skid Plate with Integrated LED Emitters would be a good first item and I love the idea of a lower lightbar vs high mount.

Thanks all.
David A.

Sponsored

 

[Gvsukids]

So my question is should I do anyting with the larger wheels and tires to prevent issues and is it worth buying a ZAutomotive Tazer to calibrate the speedo for the slightly larger wheels and tires?

Is your speedometer off?

 

[atldc9]

Have not done a complete check yet but just based on the math of the tires being 1.9% bigger it would be about 1 mile slow at 60 about 1.4 at 70.

 

[DocMike]

Where are you in Colorado? I have a taser we can check.

 

[atldc9]

I’m in Idaho Springs. Should have had the dealer do it, they had one but when I asked if the wheels were the stock wheels he said yes. Wasn’t till I got home I confirmed they were the Rubicon wheels.

 

[Gvsukids]

I’m in Idaho Springs. Should have had the dealer do it, they had one but when I asked if the wheels were the stock wheels he said yes. Wasn’t till I got home I confirmed they were the Rubicon wheels.

They are stock wheels, just for a Rubicon.

Where are you in Colorado? I have a taser we can check.

I don't think you can marry a Tazer with another vehicle without a paid key.

 

[DocMike]

Yeah, I'm not really sure. But worth a shot!

They are stock wheels, just for a Rubicon.

I don't think you can marry a Tazer with another vehicle without a paid key.

 

[Free2roam]

I've got Rubicon take off tires on my diesel. As far as I can tell with a gps or speedo app it's not that far off at 70. Even the dealer said they can't adjust it. Which I found weird.
As far as the diesel.
I run Hot Shots Secret every tank full for more lubricity in the pump.

 

[atldc9]

They are stock wheels, just for a Rubicon.

They are stock but a the diamater is different so it will change things a little bit. Sounds like about 1.8% on the speed. Most things I have found now say if it's less then 3% don't worry about it.

 

[Mr._Bill]

Even though some of the wheel sizes may be different, the overall diameter of the various factory installed tires are supposed to be close enough that no adjustment is needed when swapping them around.

 

[sass JT]

popping in to say hi from foco and welcome

 

[Rahkmalla]

Have not done a complete check yet but just based on the math of the tires being 1.9% bigger it would be about 1 mile slow at 60 about 1.4 at 70.

circumference is a function of pi, so when comparing two wheel speeds, eliminate pi from both sides of the equation to simplify the math. And since circumference is inversely proportional to revolutions to per mile at an even rate, you don't even need to do that math (but if you did, it would be the same). So a tire with a diameter that is 2.026% bigger will be exactly 2.026% faster and you can judge this all by simply dividing 32.71 (285/70r17) by 32.06 (255/70r17) without even involving pi or getting into revolutions per mile. This is not a one-off bit of luck at this particular size, it's formulaic across the range.

2% is a mile slow at 50, not 60. But you were correct at 1.4 at 70.

Most speedometers are about 3% over from the factory, because while the US allows ±10% variance on an OEM speedo, countries like the UK state that while a speedo can be off, it can never read slower than the vehicle is actually traveling. Other countries have similar laws i've been told, but I only ever bothered to look them up for the US and UK. Since all manufacturing has tolerances, and since the acceptable tolerance range for all countries is always going to be over, it makes a lot more sense to manufacture speedometers with a target like +3%(±2%) than it would to manufacture to the tolerances of 0%(+5%). You end up with a lot more usable units when your tolerance has a variance in either direction of the manufactured goal rather than too big=fine, too small=garbage.

So what should you do about a 2% speed increase from changing tire sizes? Don't worry about it. Personally I went from metric 33 to metric 35s (5.2% increase) and i'm not even bothering with a recal.

 

[atldc9]

Thank you,

I knew I would fine people way smarter then me on this forum.

 

[vegajf]

Download a free GPS speedometer app on your phone and you can see how close the speedo is.

 

[Sprinkler-Fitter]

Have not done a complete check yet but just based on the math of the tires being 1.9% bigger it would be about 1 mile slow at 60 about 1.4 at 70.

Why is it worth worrying about for about 1 mile an hour?

Sponsored