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What 18" tyres ?

Posted: Mon Nov 01, 2010 6:12 pm
by M 80NGO
Ok guys i have asked this question before but i just need to make sure that the info i have is correct before spending my hard earned mullah, this is the origional topic

http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=43591

I currently have 18" wheels on my 4x4 AFT they came with 225/40 18 tyres which are giving my speedo a 10% negative reading according to my sat nav, i have been advised by the nice people on this site that i should infact be using 245/40 R18 tyres to get the rolling radius to almost the same as the standard 15" set up, i have been offered a good part ex on my tyres for a set of partworn 245/40 18's but i just want to be 100% that these tyres will cure my speedo woes and that there will be no arch fouling / rubbing issues.

Soory for having to ask again but i just want my van to be right.

Thanx.

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 6:23 pm
by mikexgough
M 80NGO wrote:Ok guys i have asked this question before but i just need to make sure that the info i have is correct before spending my hard earned mullah, this is the origional topic

http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=43591

I currently have 18" wheels on my 4x4 AFT they came with 225/40 18 tyres which are giving my speedo a 10% negative reading according to my sat nav, i have been advised by the nice people on this site that i should infact be using 245/40 R18 tyres to get the rolling radius to almost the same as the standard 15" set up, i have been offered a good part ex on my tyres for a set of partworn 245/40 18's but i just want to be 100% that these tyres will cure my speedo woes and that there will be no arch fouling / rubbing issues.

Soory for having to ask again but i just want my van to be right.

Thanx.
Using this I would have said 225/45/18 based upon 215/65/15..... I am on 17's with 225/55/15 101w xl supplied by Wheelquick.... with no rub....
I guess the owners with 18's will be along soon with their set ups

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 7:29 pm
by You've Been Bongod
i have 225 45 18 and speedo is 4mph slower than should be my tyres were £250 fitted

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 9:06 pm
by valley boy
I run 245 X45X18 all round with no problems except the speedo compared to sat nav reads 5-7 mph fast on a 2.5 2 wheel drive aft i've learned to live with it.

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 9:28 pm
by chakota
I run 235/45/18 's on mine and reads same as above about 7mph faster.

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 10:20 pm
by SPARKYSSS
Sorry to sound like a complete thickie (not for the first time) but if i were to acquire some nice 18s what are the exact tyre codes i need to look for please including load ratings

thanks

marc

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 10:24 pm
by mikexgough
SPARKYSSS wrote:Sorry to sound like a complete thickie (not for the first time) but if i were to acquire some nice 18s what are the exact tyre codes i need to look for please including load ratings

thanks

marc
Load rating is important at least 96...... But many 18's that are "Bongo Friendly" to fit are made in 95 rating...... My 17's are 101's

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 10:27 pm
by SPARKYSSS
So what are all the numbers on your tyres please as im trying to sort costings out etc

thanks

oh and what make??

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 10:28 pm
by M 80NGO
My god i'm even more confused than when i first started :lol:

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 10:41 pm
by mikexgough
SPARKYSSS wrote:Sorry to sound like a complete thickie (not for the first time) but if i were to acquire some nice 18s what are the exact tyre codes i need to look for please including load ratings

thanks

marc

This site may help

This compares your Standard size and you can match a close as for larger wheels for rolling radius etc

As an example of sizes...... Mine are 225/55/17 W 101 XL ........ YBB has 225/45/18 on his not sure of his load rating.....

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 10:44 pm
by SPARKYSSS
Brilliant thanks a lot Mike

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 10:56 pm
by M 80NGO
mikexgough wrote:
SPARKYSSS wrote:Sorry to sound like a complete thickie (not for the first time) but if i were to acquire some nice 18s what are the exact tyre codes i need to look for please including load ratings

thanks

marc

This site may help

This compares your Standard size and you can match a close as for larger wheels for rolling radius etc

As an example of sizes...... Mine are 225/55/17 W 101 XL ........ YBB has 225/45/18 on his not sure of his load rating.....

Yeah mike thats a good site now if standard front 4x4 tyres are 215/65 R15 then 225/45 R18s are near as damn it to the same rolling radius can anyone confirm the correct standard tyre sizes for a 4x4 as i believe the fronts are 15" and the rears 16" ?

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 11:01 pm
by SPARKYSSS
arghhhhhhhhhhhhhhhhhh thats another point - mine is a 2 wheel drive v6 tintop so i guess i can go same on all 4 corners???

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 11:02 pm
by 2sticks
M 80NGO wrote: I currently have 18" wheels on my 4x4 AFT they came with 225/40 18 tyres which are giving my speedo a 10% negative reading according to my sat nav, i have been advised by the nice people on this site that i should infact be using 245/40 R18 tyres to get the rolling radius to almost the same as the standard 15" set up, i have been offered a good part ex on my tyres for a set of partworn 245/40 18's but i just want to be 100% that these tyres will cure my speedo woes and that there will be no arch fouling / rubbing issues.
Thanx.
Your 225/40 18 inch tyres should put the speedo out by 3 to 4 mph fast. I would suggest
whoever fitted the 18 inch wheels tried to calibrate the speedo by moving the needle and
finished up making it worse. As the deflection is linear, I would stay with the tyres you have
and calibrate the needle to your sat-nav.

As said previously, 225/45 18 inch are an almost an exact match for original 215/65 15 inch.

Re: What 18" tyres ?

Posted: Mon Nov 01, 2010 11:04 pm
by M 80NGO
SPARKYSSS wrote:arghhhhhhhhhhhhhhhhhh thats another point - mine is a 2 wheel drive v6 tintop so i guess i can go same on all 4 corners???

My 4x4 has the same size all round, i believe that they come with 15's up front and 16's at the rear but due to the differance in tyre diamater the rolling radius is the same so my 18's are all the same .