taller tyres on MG5?

[Antjp]

I check the cars speedo against phone GPS, TomTom satnav and Dragy. XPower is spot on with 245/45/18”s vs the stock 235/45/18’s that under-read slightly.

MG5 on stock 215/50/17’s is out by 1 at 30-40mph and 2 at 70mph - having checked tyre sizes I’m considering either 225/50/17’s (+1mph) or 215/55/17’s (+2mph)

All based on new tyres/full tread.

I use this website. I base it on 205/60/16. My Speedo with these wheels is bang on based from digital dash & google maps on CarPlay. Then I compare tyre sizes based on circumference to keep a accurate Speedo.

Tyre Size Calculator

A better easy to use tyre size calculator. Use our tyre size calculator to find tyre diameter, width, sidewall, circumference, and revolutions per mile.

tiresize.com

 

[salty]

Don’t think many would dare risking their insurance voiding a claim by putting on non-approved tyres just to improve looks?

But then again different countries, different rules, in Germany one can do this
View attachment 31619

A bit of a late reply. But you can do exactly the above here, if you want to.
As long as you inform your insurance, exactly what you've done, your totally legal. As for any possible warranty claims, they may knock back on, because of the mods, well I'm afraid, ya takes ya chance, there. Plenty do though.