Tyres - Mixed up load ratings
Tyres - Mixed up load ratings
Author
Discussion

shost

Original Poster:

881 posts

173 months

Sunday 14th December 2014
quotequote all
I recently sorted the replacement tyres on my elderly father's car. I picked mid range premiums with a speed and load rating of 93V as it was suitable for the vmax of the car. It had 93W before but I wanted to keep costs down a bit too for the old man.

He had a bad puncture last week and wanted a quick matching replacement. He found a place who then accidentally fitted a narrower tyre. He noticed after a couple of days and went back.

They have now fitted the correct make and size but it is 97W XL instead as that is "the correct tyre from our database" and it's what they had in stock. And charged the difference. The old man didn't agree but they talked him round. I don't agree so I rang to contest. I used the analogy that it's like having different types of shoe on, even if they fit. They totally disagree and told me I don't know what I'm talking about and told me the three other tyres are wrong, and they're beyond reproach.

Am I being a knob or are they? The car is a medium performance fwd saloon and the new tyre is on the front axle.

Unfortunately in my old man's panick to get the car fixed he didn't run it past me first.

PositronicRay

29,045 posts

213 months

Sunday 14th December 2014
quotequote all
Tyres are over specified for the speed of the vehicle. So if the top speed of your car is say 145mph instead of specifying a V (Up to 149)they will go up to the next speed rating W.

You may (in this country) put a lower speed rating on but may affect ins if not adhering to recommended manufactures specs.

TooMany2cvs

29,008 posts

156 months

Sunday 14th December 2014
quotequote all
shost said:
Am I being a knob or are they?
What's the handbook/tyre sticker say?

shost

Original Poster:

881 posts

173 months

Sunday 14th December 2014
quotequote all
Option wheel rims. But had the car since new (ex dealer). Been through the service history files. Yup we've two volumes. Can only see reference to 93V size.

Wheels are Sirus Volvo 16"

TooMany2cvs

29,008 posts

156 months

Sunday 14th December 2014
quotequote all
shost said:
Option wheel rims. But had the car since new (ex dealer).
But what load rating does it show as a minimum?

[quote-shost]Can only see reference to 93V size.
If the lowest load rating shown in the book/sticker is above 93, then 93 is probably inadequate. Same for V speed rating. If 97XL is the next load-rating up available in the size you're after, then there y'go. But if the sticker/book shows 93 or lower, then 93 is going to be fine.

Edited by TooMany2cvs on Sunday 14th December 19:34

Ozzie Osmond

21,189 posts

276 months

Sunday 14th December 2014
quotequote all
PositronicRay said:
You may (in this country) put a lower speed rating on but may affect ins if not adhering to recommended manufactures specs.
Two different things - speed rating and load rating. Both matter.

As you say, any change from original tyre specification is potentially a "modification" for insurance purposes.

shost

Original Poster:

881 posts

173 months

Sunday 14th December 2014
quotequote all
Can't see anything in the handbook stating minimum load rating or speed rating.

More concerned by one tyre being extra load 97W (XL) and the others being 93V. The tyre fitters insistence that they are not wrong to offer a matching tyre is my second concern.

The car has covered over 170,000 miles with 93 load tyres so I can't say I'm worried about the tyres being underrated.


AnotherGareth

215 posts

204 months

Monday 15th December 2014
quotequote all
shost said:
Can't see anything in the handbook stating minimum load rating or speed rating.
Look for a plate or sticker under the bonnet - will specify maximum loads for each axle. Fitting suitable tyres to support the maximum permitted axle weight is a legal requirement.

You can find lots of places online to relate the axle weight to load index - you need each tyre to have a reasonable margin over half the maximum axle weight for the axle to which it is fitted.

Speed rating is not a legal requirement, providing you use the vehicle within the tyre limits.

OvalOwl

981 posts

161 months

Monday 15th December 2014
quotequote all
AnotherGareth said:
Speed rating is not a legal requirement, providing you use the vehicle within the tyre limits.
The size speed and load rating must match across an axle to be legal.

AnotherGareth

215 posts

204 months

Monday 15th December 2014
quotequote all
OvalOwl said:
The size speed and load rating must match across an axle to be legal.
Agree that the size must match (within certain tolerances, for example aspect ratios of 80% and 82% where the other sizes are the same are permitted, and a temporary spare wheel is OK) and type of construction must match (cross-ply, radial, run-flat) but as far as I can see neither the Highway Code, the MOT testers manual, nor The Road Vehicles (Construction and Use) Regulations 1986 require that load and speed ratings must match across an axle on cars.

If you think differently, can you point to the legal requirement?

CraigyMc

18,369 posts

266 months

Monday 15th December 2014
quotequote all
OvalOwl said:
AnotherGareth said:
Speed rating is not a legal requirement, providing you use the vehicle within the tyre limits.
The size speed and load rating must match across an axle to be legal.
haha, no. That's just bks.

Sheepshanks

41,215 posts

149 months

Monday 15th December 2014
quotequote all
I wouldn't be happy about having one XL tyre (unless they should all be XL).

Apart from the intuitive mis-match, for a given load index, XL tyres need higher pressure to carry the same weight. As it happens, between standard 93 and XL 97, it's very close, but it's not exactly the same.

OvalOwl

981 posts

161 months

Monday 15th December 2014
quotequote all
CraigyMc said:
OvalOwl said:
The size speed and load rating must match across an axle to be legal.
haha, no. That's just bks.
Mea culpa. boxedin