wheel nut size

Early Bay Forum

Help Support Early Bay Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
185 65 R15 XL (extra load)

So you have changed your effective gearing and speedometer calibration, by having a smaller external circumference than 185/80 R14 tyres, resulting in a higher engine RPM and higher indicated road speed for a given true road speed. The tyre size for 15 inch wheels, closest in external circumference to that of 185/80 R14 tyres, is the 195/70 R15 which is what is used on the VW Transporter T4.
 
Last edited:
So you have changed your effective gearing and speedometer calibration, by having a smaller external circumference than 185/80 R14 tyres, resulting in a higher engine RPM and higher indicated road speed for a given true road speed. The tyre size for 15 inch wheels, closest in external circumference to that of 185/80 R14 tyres, is the 195/70 R15 which is what is used on the VW Transporter T4.
It’s a lot better than the 175 55 R15’s that have been on it since I bought it. These new ones do 26 revolutions more per Km more than the ones you mention above. I went with these as someone else recommended this size. I don’t know much about what tyres to run hence asking on another thread.

I don’t think it’s going to make that much difference to my everyday to be honest. I’ll get larger ones next time I need to swap them armed with this knowledge.

My Speedo is way off as the front tyres are not as large as the rears.
 
Last edited:
It’s a lot better than the 175 55 R15’s that have been on it since I bought it. These new ones do 26 revolutions more per Km more than the ones you mention above. I went with these as someone else recommended this size. I don’t know much about what tyres to run hence asking on another thread.

I don’t think it’s going to make that much difference to my everyday to be honest. I’ll get larger ones next time I need to swap them armed with this knowledge.

My Speedo is way off as the front tyres are not as large as the rears.
Soooo… the circumference of my tyre is 622mm and does 26 revolutions more per km than a 195 70 R15, which works out to be 16 meters less per km while driving. Knowing the logic of old rubbish vans, this very, very minor reduction in gearing would make hills a little easier with my heavy Westfalia.

16 meters.
 

Latest posts

Top