Adj Speedometer - Need Ram Tech answer

[hanadarko]

On a 2013 1500 Laramie 4x4, I need to know if the dealer can adjust the speedometer for a larger tire.

The ONLY choice for OEM was:

265/70R17
275/60R20

Mine came with the 20" rims.

I am installing LT275/65R20 and as such are about 1" taller, which will equal lower revs per mile and an estimated 3.3% speed reading.

Per the lovely internet and calling 3 local Ram dealers:
I've been told that the dealer can adjust this AS WELL AS told the dealer can only make changes based on what tire options the RAM could come with based on the model year.

In other words if I had 17" and put the normal OEM 20" on it, they could adjust the ECM. The other responses are "just give us the circumference and RPMs/Mile and we can calibrate this. All of the dealers said it would be free as long as I got the tire mounted there. Currently they are brand new and sitting in my garage, awaiting install.

I know I can buy an aftermarket tuner to do this so it IS possible but to spend that kind of money ($200+) is rather insane, even for me.

Does anyone work for Dodge/Ram that can answer this once and for all?

PS. I went the same run-around getting my DRLs active and ended up being told by 3 local dealers "can't be done" - yet drove 2hrs to a Chicago dealer and had them activated for 1hr of labor time. Perfect.

 

[DeathMachine73]

Not a tech, but i had my local dealer adjust my speedo from factory to 35" tires... they charged 50 bucks and its further off now than it was after just changing the tires. I've checked with gps. Im just waiting to get a tuner and do it myself.

 

[hanadarko]

Not a tech, but i had my local dealer adjust my speedo from factory to 35" tires... they charged 50 bucks and its further off now than it was after just changing the tires. I've checked with gps. Im just waiting to get a tuner and do it myself.

See? - This is the kind of stuff I find so annoying at dealers......
I'd take it back and either tell them its worse off and demand a refund of $50 or force them to re-adjust it, presuming thats possible.

These dam tuners are not cheap and I really have no other use for it but for the speed adjustment, so its really hard to justify.

Thanks...

 

[bryan28]

I understand what you're saying about dealers and if they adjusted it and it was still off I'd ask for a refund too. However, it's not really their problem if you decide to change tire size. That's on you to figure out how to adjust everything for the tires you decided to put on.

 

[hanadarko]

I understand what you're saying about dealers and if they adjusted it and it was still off I'd ask for a refund too. However, it's not really their problem if you decide to change tire size. That's on you to figure out how to adjust everything for the tires you decided to put on.

I agree but for one point.
If a dealer SAYS or CLAIMS they can fix/adjust something, it ought to be done or it's free.

For example, when I called around to get my DRLs active I was told by all 3 dealers "No problem - we can easily do that. 1hr labor".

First place - Couldn't do it. Didn't charge.
Second place - Couldn't do it. Tried to charge.
Thats when things went like this:

"$105? for doing nothing?"

Well we spent time "trying" to enable your DRLs and we were unable to.

"Yes but I asked PRIOR and you said NO problem. So if there is a charge, YOU'RE going to HAVE a problem".

Needless to say, I was NOT charged and left.

Third place - Did the work. Charged me 1hr and all was well.

So, the point is - if you (dealer) tell me you're going to do/fix something - it will be fixed or I'm not paying it -or- I will be back until it IS fixed or I am refunded.

Dude, in your case, they made it worse!


..Anyways, I was TOLD it was not a problem to adjust, so as history dictates, don't tell me you CAN, then fail and try to charge me.

It doesn't work like that. This Service Manager knows me very well now.....
It will be adjusted and accurate or I won't be paying.

Dealers rip people off all the time. It's always a fight but one I always will take on.
The dealer is my last place of choice.

 

[Tach_tech]

Years ago we used to be able to adjust the speedo by programming the revs per mile. For a few years now we can only choose from factory available tire sizes. You'll need to go to the aftermarket if you want to go bigger then any of the stock sizes.

There's your answer.

 

[stricnine]

The stealership can only adjust to the max oem offered height. For this reason you will need an aftermarket speedo calibration tool to adjust. Since I am running 37s and the dealership knows they can't calibrate that size, they threw in a hypertech speedo calibration tool as part of my truck purchase. This is due to the rim and tires already being included on my truck. Also, should you do this yourself ensure that you input the actual tire height, measure it. This will ensure you calibrate correctly on the first try.

 

[hanadarko]

The stealership can only adjust to the max oem offered height. For this reason you will need an aftermarket speedo calibration tool to adjust. Since I am running 37s and the dealership knows they can't calibrate that size, they threw in a hypertech speedo calibration tool as part of my truck purchase. This is due to the rim and tires already being included on my truck. Also, should you do this yourself ensure that you input the actual tire height, measure it. This will ensure you calibrate correctly on the first try.

Is this option the absolute cheapest out there?
I'm not really interested in changing fuel mappings or engine parameters. The OEM performance is more than fine for me...

Thanks guys

 

[stricnine]

Is this option the absolute cheapest out there?
I'm not really interested in changing fuel mappings or engine parameters. The OEM performance is more than fine for me...

Thanks guys

It reads and clears codes and can calibrate your speedometer, that's it. No performance tune.
Here's a pic for you.

 

[DeathMachine73]

See? - This is the kind of stuff I find so annoying at dealers......
I'd take it back and either tell them its worse off and demand a refund of $50 or force them to re-adjust it, presuming thats possible.

These dam tuners are not cheap and I really have no other use for it but for the speed adjustment, so its really hard to justify.

Thanks...

Well they were going to charge more, they told me it wasnt perfect, but that it should be closer. So i doubt a refund would happen as they'd say that was to pay the guy to **** around with it for a while. I was planning a tuner anyways for other reasons so im not super worried about it. At this point i know where to set cruise for the highway to be going the speed limit.

 

[init6]

Well they were going to charge more, they told me it wasnt perfect, but that it should be closer. So i doubt a refund would happen as they'd say that was to pay the guy to **** around with it for a while. I was planning a tuner anyways for other reasons so im not super worried about it. At this point i know where to set cruise for the highway to be going the speed limit.

Speed limits are optional. I set the cruise for what I feel comfortable with at the current time and to hell with everyone else. I don't really even look to see what the speedometer says. . Too slow? I stay in the right lane. Too fast? Left lane. No worries.

 

[DeathMachine73]

Speed limits are optional. I set the cruise for what I feel comfortable with at the current time and to hell with everyone else. I don't really even look to see what the speedometer says. . Too slow? I stay in the right lane. Too fast? Left lane. No worries.

Thats how i used to feel haha, especially when i had my cobalt ss. After the speeding ticket im good on just setting it around the limit haha