3 replies to this topic

[minisilverbullet]

I want to change my 13s to 10s, but nothing is ever simple!

The car is a cooper SPi, i don't know the current ratios or final drive but i assume it will be the same as all spi coopers.

I had a look on Guessworks ration calculator, which is great! But can someone put it in simple terms for me.

Dropping to 10s will mean:

The acceleration is slower?

Lower top speed?

Higher rpm on the motor way (bad for fuel economy)?

How bad will the speedo be out?

[minisilverbullet]

SO engine code is 12A2EK71 - which according to guessworks is


Source Vehicle : Mini Cooper Spi (Japan) Engine type & CC : A+ 1275 cc Transverse mounted Fueling : Engine features : Air Conditioning 10.1:1 Compression Ratio Gearbox features : Std. Ratio Rod Change gearbox with Pot Joints 3.21:1 Final Drive

Although its not a japanese model with aircon, but a late german export SPI.

[TheOriginalMiniator]

This is the converter which you need!! I've used it for all my alloy wheel changes!

http://www.kouki.co....size-calculator


assuming your using a 175/50/13 currently and are changing to a 165/70/10

Your speedo at 30mph = 28.8mph actual
Your speedo at 60mph = 57.6mph actual

Edited by TheOriginalMiniator, 06 March 2012 - 06:40 PM.

[Bishop IRL]

My speedo is reading the other way round!

My speedo at 30mph = 34mph actual

Im on 10's and as she is an '86 Mayfair, was probably on 12's when new!!!