Largest tire without recalibrating speedometer?

[Bob 07064]

What's the largest tire I can put on my two door without recalibration of the speedo?

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[Doc Brown]

What trim? Sasquatch?

 

[Bob 07064]

Base, so I can really make it my own

 

[Gamecock]

What's the largest tire I can put on my two door without recalibration of the speedo?

That’s up to you, you don’t ever have to do it…you can see the effect of it here:

https://tiresize.com/speedometer-calibration/

 

[Bob 07064]

 

[Erock]

At highway speeds, 1” difference in tire height changes the speed around 2 1/2 mph or so. Crude numbers... but it was what I used on older vehicles instead of changing the speedometer gear

 

[Monster1926]

I’d say 33s. After that you’re going to want to get the speedo recalibrated and I think your transmission shift points will be different to with larger tires.

 

[kodiakisland]

I’ve never recalibrated the speedo and always run bigger tires. I can add 2-3 in my head most days. My initial tire swap will be off by 4%, so I’ll just remember when the speedo says 100 it’s really 104.

Wonder how dead on accurate the speedo is in the first place?

 

[kodiakisland]

I’d say 33s. After that you’re going to want to get the speedo recalibrated and I think your transmission shift points will be different to with larger tires.

Shift points should be based on rpm, not mph.

 

[Monster1926]

Shift points should be based on rpm, not mph.

Ok

 

[kodiakisland]

Ok

Sport mode should shift at higher rpms and that should help with the bigger tires, both in increased weight and reduced gearing. I prefer to row my own, so I don’t have to worry about that.

 

[Monster1926]

Sport mode should shift at higher rpms and that should help with the bigger tires, both in increased weight and reduced gearing. I prefer to row my own, so I don’t have to worry about that.

I don’t have sport mode. If I get a bigger tires I’ll just re-calibrate. Tune and possibly bigger turbos are the plan.

 

[kodiakisland]

I don’t have sport mode. If I get a bigger tires I’ll just re-calibrate. Tune and possibly bigger turbos are the plan.

Don’t forget the gears. That’s my biggest concern when going to bigger tires. Correct gears cure a lot of ills bigger tires bring.

 

[ZackDanger]

You don’t ever have to recalibrate for bigger tires. It’s just so your speedometer reads correctly. It’s usually a trivial matter to do with the right tool, but I wouldn’t worry about it too much if you don’t have the ability at first.

As pointed out, depending on the delta between tire sizes, regearing can have a huge and vital impact.

(Not always necessary, but at a certain point, I feel it’s worth the expense.)

 

[Quinn_the_eskimo]

Someone should have a way to tap into your OBD to change it, no? I can on my gladiator using a bypass connector and an app on my phone. The connector is like $35 and use of the app is another $20. Bluetooth OBD readers run anywhere from $20-100. That allows me to reprogram most anything a dealership can.

Most sites with tire size charts have details on gearing, too - with "sweet spots" highlighted. Go outside of that and you'd need to jump up in gearing or you're putting excess strain on your driveline and bound to tear up u joints and trannys.

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