Tire Size Calculator

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PaavScan

Tire Size Calculator

#1 Post by PaavScan » Sat Sep 20, 2008 8:40 pm

Shows how much your speedometer will be out as you change tire size.

http://www.miata.net/garage/tirecalc.html

If I change tires from 255-55-18 to 285-60-18 my speedo will be out by 8.3% to slow.

Stu

ANDYD
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Tyre change...

#2 Post by ANDYD » Sun Sep 21, 2008 9:41 am

Hi Stuart,

Do you know if the 8.3% to slow will effect the computor "thinking"?
Will the computor be able to adjust for the "wrong" information it is recieving, different from the factory set up?
Im not sure if it makes a difference, just thinking out loud!

What brand/type of tyre are you considering? My 04 SE7 is due some new tyres soon, so I will be following in your footsteps (or tyre treads :? )....
Let me know what you decide and how it goes..
cheers,
Andy

PaulC

#3 Post by PaulC » Mon Sep 22, 2008 9:12 am

The only CPU based operation, (that I can think of) directly effected would be a delay in ABS activation.

I believe minimum speed of 4kph in Discovery 1, is the same as Discovery 2. So if your vehicle speed shows 8.3% slower your ABS won’t be active :shock: :D (on start-up) until your 8.3% faster than 4kph.

Of course there is a long list of “things” that will change with the larger tire diameter, few if any will have a notable or detrimental effect on Discovery 2.

ANDYD
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Tyres D2

#4 Post by ANDYD » Mon Sep 22, 2008 6:15 pm

Thanks Paul,

Thats good to know even if it dosen't effect the overall performance.

cheers,
:D Andy

DaveB
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Location: Vernon, BC

#5 Post by DaveB » Tue Sep 23, 2008 9:45 pm

I have a spare set of 18" rims if anyone wants to keep their street tires separate from their off-road tires...

Let em know and I could bring them down this week...

Dave

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