Stupid Question Time...

[Nova_Sean]

I have brought some alloys today, Astra Mk4, and dad reckons that the diameter of the wheel eeds to be the same size as what i currently have on the car otherwise the speedo will read over and will be illegal..

So atm, the diameter of my 145/80/13's is 21.25 inch

And the diameter of my 195/55/15's is 21.75 inch

Would i need to put 195/45's on?

The car isnt lowered either.

[Pistol Pete]

45 profile tyres are what usually get fitted to 15's. Most speedos over read as standard BTW....

I would consider getting it lowered aswell. It will look like a 4x4 on standard ride height and 15's.

[Nova_Tek]

I went from 145/80 R13 (or was it 145/70 R13) to 195/45 R15 with no speedo issues. The likely hood is that the very slight diameter increase has made a slightly more accurate speedo as they tend to over read from the factory as pete 58 mentioned.

It should be fine mate.

And yes get it lowered Pete 58 is right, it will look like one of them high chassis pick up trucks lol

[John]

Lol, nova speedos are not accurate anyway.

[keithrg]

Lol, nova speedos are not accurate anyway.
at 86mph on speedoe I was only clocked at 74mph :roll: in a 50. I was glad it was a speed awareness pulling and excuse to breatherlize

[michael squeak]

i went from 145/80/13 to 205/40/17

who needs a speedo

[mowgli]

http://www.pngclub.com/forum/showthread.php?t=112122

links to tyre calculators