Wheel and tyre question

[Nabsim]

Hi Ken, (@rugbyken) What size tyres did you fit?

Thanks for all the replies, I called Michelin today and they said I needed to speak to either Hymer or Fiat about changing from 15" to 16" and they also said I should use CP not C tyres but I'm thinking he was only trying to convince me to buy their Cross Climte Camping tyres.

Regards,
Del

When I thought I had to change to get the load rating I went to a proper wheel and tyre place. Their fitter had a good look over to see if bigger wheels would fit without any metalwork. If you do need to change may be worth doing similar?

 

[rugbyken]

TBF the guy i was ordering from asked the size of present tyres and model & supplied accordingly so not sure exacfly which ones i got did stand new against old & there was a significant size difference , has corrected the speedo but no noticeable improvement in speed torque or fuel consumption

 

[Caz]

There are numerous reasons to change wheel size.
Appearance; Tyre Availability; Load Ratings; Handling; Ride and no doubt others not listed.

I know, but I was asking Del what his reasons were. Which he still hasn't said.

 

[alwaysared]

I know, but I was asking Del what his reasons were. Which he still hasn't said.

Better load rating and posh new alloys from Rogue

Regards,
Del

 

[colinm]

Thanks for all the replies, I called Michelin today and they said I needed to speak to either Hymer or Fiat about changing from 15" to 16" and they also said I should use CP not C tyres but I'm thinking he was only trying to convince me to buy their Cross Climte Camping tyres.

Regards,
Del

Some years back Michelin where involved with a court case over a burst tyre on a motorhome, since then company policy has been to only recommend CP tyres on motorhomes, and for the rears to always be at max pressures, this means that they are unable to officially supply 215/75-16 tyres with the load capacity for my Fiat Ducato Maxi.

 

[alwaysared]

Some years back Michelin where involved with a court case over a burst tyre on a motorhome, since then company policy has been to only recommend CP tyres on motorhomes, and for the rears to always be at max pressures, this means that they are unable to officially supply 215/75-16 tyres with the load capacity for my Fiat Ducato Maxi.

They do a 225/75 R 16CP with a load rating of 118/116, could you use those?

Regards,
Del

 

[colinm]

They do a 225/75 R 16CP with a load rating of 118/116, could you use those?

Regards,
Del

I just use the commercial C tyre that is the right size and load index.
p.s. I could use a Conti tyre that is built to CP standards, but has to be labeled as C due to regs.

 

[rugbyken]

must say when the winter camper tyres provided with the wheels ran out ifitted the normal heavy duty commercials that i usually run on never bothered with the very expensive specialist ones

 

[Millie Master]

Why oh why change from 15" to 16" rims, what the hell is wrong with the OE specifications which are also the ones listed with the authorities?

 

[exwindsurfer]

They do a 225/75 R 16CP with a load rating of 118/116, could you use those?

Regards,
Del

Del you know I changed to 16in wheels must be 4 or 5 years ago now and had no probs apart for the speedo is 0ut not so much a 30 but at 70 om the speedo I am actually doing 74 on the Tom Tom and I am running 225 x 75 x 16 in with plenty of clearance and the only reason I change them was purely for cosmetic reason lolol

 

[exwindsurfer]

They do a 225/75 R 16CP with a load rating of 118/116, could you use those?

Regards,
Del

And that would be a YES lol

 

[sludgesurfer]

I can't speak for the original posters reasons but I looked into doing this in order to increase the ride height. I'm a windsurfer and spend a lot of time on Tiree where beach access tracks over the machair aren't great.
I've knocked those daft water drain pipes off so many times, anything which could get them (and the exhaust) a couple of inches further off the ground would be a blessing.
After looking at all the potential issues including a couple of youtube videos where people were unimpressed with the results and had reverted back to 15s, I ended up sticking with 15s and now keep so many sections of water pipe, elbows and valves that the van looks like a plumbers merchant.
I did get a new set of cross climate CPs and if I squint hard enough I can convince myself that the meatier tread gained me 1/4 inch over my old continentals which I thought were crap on wet grass. This is likely wishful thinking...but the tyres are great.

 

[exwindsurfer]

I can't speak for the original posters reasons but I looked into doing this in order to increase the ride height. I'm a windsurfer and spend a lot of time on Tiree where beach access tracks over the machair aren't great.
I've knocked those daft water drain pipes off so many times, anything which could get them (and the exhaust) a couple of inches further off the ground would be a blessing.
After looking at all the potential issues including a couple of youtube videos where people were unimpressed with the results and had reverted back to 15s, I ended up sticking with 15s and now keep so many sections of water pipe, elbows and valves that the van looks like a plumbers merchant.
I did get a new set of cross climate CPs and if I squint hard enough I can convince myself that the meatier tread gained me 1/4 inch over my old continentals which I thought were crap on wet grass. This is likely wishful thinking...but the tyres are great.

I changed my front shocks about 18 m9nths ago and while I was doing it I put 40mm spacers on the top of the shock which you can imagine lifted it an extra 40 mm this is on a 2009 citroen relay

 

[exwindsurfer]

I changed my front shocks about 18 m9nths ago and while I was doing it I put 40mm spacers on the top of the shock which you can imagine lifted it an extra 40 mm thus is on a 2009citrien relay

 

[Nabsim]

Why oh why change from 15" to 16" rims, what the hell is wrong with the OE specifications which are also the ones listed with the authorities?

Could be a few reasons, tyre choice, load rating or purely because they like the looks

 

[merl]

Del you know I changed to 16in wheels must be 4 or 5 years ago now and had no probs apart for the speedo is 0ut not so much a 30 but at 70 om the speedo I am actually doing 74 on the Tom Tom and I am running 225 x 75 x 16 in with plenty of clearance and the only reason I change them was purely for cosmetic reason lolol

That's interesting, no issues with the MOT now the Speedo reads under?
Is speedo accuracy checked at MOT?
If so at what speed/speeds and what tolerance under/over is allowed?

 

[colinm]

That's interesting, no issues with the MOT now the Speedo reads under?
Is speedo accuracy checked at MOT?
If so at what speed/speeds and what tolerance under/over is allowed?

Speedo accuracy isn't checked on MOT, but the speedo should never be less than true speed but can over read by 10%+6.25mph

 

[exwindsurfer]

That's interesting, no issues with the MOT now the Speedo reads under?
Is speedo accuracy checked at MOT?
If so at what speed/speeds and what tolerance under/over is allowed?

No speedo check at MOT

 

[mark61]

Speedos by default nearly always over read, it's a safety margin manufacturers build in, they are allowed to over read, but never under read.

I'll stick my neck out and suggest nearly everyone that puts larger tyres on, gets a reading that is closer to the real speed, even if it is slightly under reading.
There are limits obviously, I'm talking about an increase in tyre that would not require any further modification to body, suspension etc.

 

[merl]

Speedo accuracy isn't checked on MOT, but the speedo should never be less than true speed but can over read by 10%+6.25mph

Is that something that gets certified/checked at the production/sign off stage then Colin? Seems odd having a set of rules that are not checked at the MOT.