Different Tyre aspect ratio on one wheel

trevd01 · Post by **trevd01** » Tue Feb 05, 2008 6:57 pm

Our '99 not-winter-spec Bongo has a plate showing 195/80 and 215/70 as well as 195/70 and 215/65.

I have a picture which I will post and then someone who reads Japanese can translate what it says next to the larger size tyres.

Be interesting if it said 'you can fit the same size all round'

{Photobucket down at the moment - will post picture later}

francophile1947 · Post by **francophile1947** » Tue Feb 05, 2008 7:04 pm

Hmmm - I wonder how you adjust the speedo with 195/80s on - you'd be doing 63.6mph whilst the speedo read 60, which I believe is illegal

trevd01 · Post by **trevd01** » Tue Feb 05, 2008 8:12 pm

google translate wrote: 正面= Front
後部 = Rear

I think thats what is says

So the whole plate says:

Front 195/70R15 92S 200(2.0)
Rear 215/65R15 96S 240(2.4)
Front 195/SR15, 195/80R15 96S 180(1.8 )
Rear 215/70R15 98S 240(2.4)

Also has higher load ratings for the bigger tyres, and a lower tyre pressure on the front

Photobucket still down

dandywarhol · Post by **dandywarhol** » Tue Feb 05, 2008 10:00 pm

francophile1947 wrote:Hmmm - I wonder how you adjust the speedo with 195/80s on - you'd be doing 63.6mph whilst the speedo read 60, which I believe is illegal

Wouldn't affect it franco - the speedo reads the rear wheel speed from the gearbox.

francophile1947 · Post by **francophile1947** » Tue Feb 05, 2008 10:04 pm

dandywarhol wrote:
francophile1947 wrote:Hmmm - I wonder how you adjust the speedo with 195/80s on - you'd be doing 63.6mph whilst the speedo read 60, which I believe is illegal
Wouldn't affect it franco - the speedo reads the rear wheel speed from the gearbox.

Yeah - I should have gone further and compared rears as well in my post. Thing is normal rears are 215/65 but 215/70 (when used with the 195/80 fronts) - this will surely make speedo under-read.

dandywarhol · Post by **dandywarhol** » Tue Feb 05, 2008 10:52 pm

A fraction over 3%

trevd01 · Post by **trevd01** » Tue Feb 05, 2008 11:20 pm

Photobucket's back:

Here's the photo of the actual plate:

Anyone want to translate the rest?

apole · Post by **apole** » Wed Feb 06, 2008 9:47 am

Hi,

I used http://www.miata.net/garage/tirecalc.html to calculate the difference in diameter between the different choices.

I found very little difference between 195/80/15 and 215/70/15 tyres, hence I replaced the 65 section tyre with a 70.

Now they all match.

When I offered up the two different tyres at the fitting shop there was quite a difference is size, about an inch.

Glad it's sorted now at least.

My plate doesn't have so much options on it from memory, don't have the car with me today but will take a pic and post as soon as I can.

Andy