Tyre Pressures help please.

Technical questions and answers about the Mazda Bongo

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The Duke

Tyre Pressures help please.

Post by The Duke » Fri Jul 17, 2009 8:36 pm

I have not had my Bongo (2.5D 2WD auto) long, it came with 225/45 R18 tyres on all four corners, I have kept the pressures at what they were when I purchased it but am going on a long journey with all the kids and large load over the weekend, what is the best pressures to have the tyres at, the handbook mentions pressures but I ](*,) don't have the standard size tyres.

Any advice would be greatly appreciated.

James
Yeovil
francophile1947
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Re: Tyre Pressures help please.

Post by francophile1947 » Fri Jul 17, 2009 8:46 pm

It's anybody's guess. I run my 225/55x17s at 40PSI - just a case of trial and error I'm afraid - play with the pressures until it feels right and handles well.
More importantly, have you checked the load rating of the tyres? I couldn't find any, of your size, with the minimum 96 rating required on the rears, on the Mytyres website :shock: Underrated tyres have been known to shred, which you really don't want with the kids and a full load on board #-o
John
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BongoMTBer

Re: Tyre Pressures help please.

Post by BongoMTBer » Sat Jul 18, 2009 2:08 pm

In addition to feel and handling, you will need to monitor the tread wear over a period of time. An increased wear rate of the crown of the tyre in relation to the shoulders indicates too much pressure. Conversely, an increased wear rate to the shoulders in relation to the crown indicates too little pressure.

I run mine at 40 psi.
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Re: Tyre Pressures help please.

Post by scanner » Sat Jul 18, 2009 2:56 pm

francophile1947 wrote:More importantly, have you checked the load rating of the tyres? I couldn't find any, of your size, with the minimum 96 rating required on the rears, on the Mytyres website :shock: Underrated tyres have been known to shred, which you really don't want with the kids and a full load on board #-o
Ditto........from what I can see that size only seems to be made in 91 or 95 load index.

If yours are 95's you MAY just get away with it, but if they are only 91's you are risking disaster and the possibility of an insurer refusing to pay out and prosecution for unroadworthyness into the bargain.
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