Changing from 215/60/17..

[BrenR]

Hi,

I was looking to change my wheels to a set of sportline. Currently have standard Devonports with tyres 215/60/17. Changing to 255/45/18 would see no change in 'filling' the arches, in fact a 2mm increase in gap.

What sizes would people recommend going on a Sportline wheel to help fill the gap? I would like to keep comfort etc so would rather not go bigger than 18.

The van already has H&R 50mm springs fitted.

Thanks

 

[Rado]

stock diameter is 69 cm, 70 or71 cm is good option , speedo is not too much out ,car is not slower and looks better
most common tyres are 235/55 r18 or 255/45 r19
245/50 r18 or 245/45 r19

 

[BrenR]

Thanks for reply. Am I reading this right, that with 235/55 R18 my speedo would read 60mph but I would actually being dong 52mph?

https://www.willtheyfit.com/index.php?width=205&aspect=55&diameter=16&wheelwidth=6.5&offset=40&width2=235&aspect2=55&wheel_size=18&wheel_width=9-5&offset2=20

 

[Paynewright]

Speedo’s usually under read anyway. I went from std 16s to 235/50R18 and the speedo reads accurately now (so no safety margin, Officer!)

Ian

 

[The Van Cave]

Thanks for reply. Am I reading this right, that with 235/55 R18 my speedo would read 60mph but I would actually being dong 52mph?

https://www.willtheyfit.com/index.php?width=205&aspect=55&diameter=16&wheelwidth=6.5&offset=40&width2=235&aspect2=55&wheel_size=18&wheel_width=9-5&offset2=20

No, the will they fit site is slightly confusing in the way it presents that data, but it means that theoretically, when travelling at 60mph your speedo would display 52.

That isn’t accurate for 2 reasons though. you haven’t used your Devonport size as a comparison and as has already been said, speedos are calibrated to over read from the factory so the effect would be less.

If you compare the 235/55 18 to the 215/60 17 on your Devonports you’ll see the error isn’t anywhere near that big.

 

[BrenR]

No, the will they fit site is slightly confusing in the way it presents that data, but it means that theoretically, when travelling at 60mph your speedo would display 52.

That isn’t accurate for 2 reasons though. you haven’t used your Devonport size as a comparison and as has already been said, speedos are calibrated to over read from the factory so the effect would be less.

If you compare the 235/55 18 to the 215/60 17 on your Devonports you’ll see the error isn’t anywhere near that big.

Thanks, I must have closed and reopened the page and didn't notice it wasn't showing my current setup.

 

[Kind of Blue]

I believe that many will agree with ChrisR on this. The OEM fit tyres usually induce the speedometer to display an over estimate of the correct speed. This is deliberate as it is law not to, under read at all and or to over read by more than a certain %. I believe. That occasionally when we select a slightly over diameter tyre that the speedometer might read as accurate, by confirmation of GPS over a reasonable distance. Speedometers are not always absolutely accurate or inaccurate to the same extent across the range in any case. So it may be wise to take care when going up a small amount in diameter and do not exceed the speed limit at all so far as the speedometer reads or it may be at you peril.

Remember, although most Police Authorities give some grace when recording the speed of motorists, usually not exceeding 10% + 2mph they do not have to do so. There are some notorious Police Authorities, that will prosecute for even 1 mph over any limit. The most infamous being North Wales Police. There are others, some are very aggressive in catching people out by fair and foul means. Including tailgating dangerously close to the unaware in very much unlikely older unmarked vehicles. The officers sometimes also remove safety vests. It is also more likely that to be followed for such purposes by agencies other than the Police. So do not go too big over diameter and if you do so ask someone to kindly recalibrate your speedometer. Enjoy your new tyres.

 

[Dannyb6467]

Have a look at 235/60/18......fills the arches and no rubbing whatsoever.

 

[BrenR]

Have a look at 235/60/18......fills the arches and no rubbing whatsoever.

Even with 50mm H&R fitted?

 

[Dannyb6467]

Spacers or dropped?

 

[Dannyb6467]

Ahh sorry.....see it now. Yes will be an issue there. I'm on standard suspension. Sorry bud.