I've had my curent car for over two years now. Put the spare on receently after a puncture - it's hardly worn.
However its 165 and all the other are 185
Certainly the rims {Volvo alloys} look the same.
Will the narrower tyre cause any probs?
Certainly I've not noticed any.
Thanks
Alex
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It depends on the profile, whether it is on the front or the back, whether you are front or rear drive, type of suspension, all sorts of things. What depends is in what circumstances things may go wrong, and how. Get that 185 replaced and in the meantime blow the 165 up a bit and ca' canny!
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It's an MOT failure, and probably illegal.
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Perhaps not advisable, and I wouldn't run it more than absolutely necessary before getting a matching replacement, but 'illegal'? The emergency spare that came with my wife's Civic looked like a wheelbarrow wheel - about two-thirds the width of the standard tyre and one third the contact area...
P.
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Basically, all tyres fitted to roadwheels should be the same size. Space saver spare wheels are a bit of a grey area, but odd sized tyres don't conform to construction and use regs. and are an automatic MOT failure.
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Sorry, same tyre type and size on same axle. Fitting two space saver wheels on the same axle would be acceptable.
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I ran a BMW 3 series for some time with a 185 60 and a 195 65 on the rear. i did not notice a bit of difference in the handling. The MOT man didn't comment or did not spot it. Of course this is not advisable practice but is it dangerous?
Peter
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Citroen CXs in the 70/80s were designed to run on different tyre sizes front and rear so the spare could never match both.
Also many current cars have a spare of the smallest size (not spacesaver) fitted to that vehicle and this isn't increased when the car is fitted with larger tyres on sporty models. Sometimes these spares are marked with a label on the rim advising pressure and speed requirements.
So it is a grey area and it would be hard for a prosecution to succeed when thousands of vehicles were sent from the factory like it.
David
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Different diameters at the driven end must mean the differential is operating continuously?
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Thanks for your thoughts.
The MOT people never even looked at the spare - I had only looked at it when I bought the car and I had checked that it had not gone flat a couple of times.
I go to a MoT 'while U wait place' - incidently my barber and dentist provide a similar 'while u wait service' no need to leave your car, or indeed head and return later.
Most times I go for the MoT {twice per year as two cars}, I actually help, I sit in the car, operate the lights, horn, etc., start and stop the engine.
Clearly the space saver wheels are a 'Grey issue' .
On a previous car, the at the MoT, they never even spotted that the middle rear seat belt was missing.
Alex
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165 and 185 are tyre widths not diameters - or am I wrong?
Any car with a diff can cope with different diameters - requied for all cornering -only old Landies have locked difs?
Volvo use a 'poer lock' diff on both cars and trucks.
Alex.
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Alex,
I hope I've got this right.
The aspect ratio of tyres is fixed so that the height is a percentage of the width. Hence a 165 70 series has a height (profile) 70% of 165mm. So your 185, if the same "profile" will be taller than the 165 and have a greater rolling radius.
So often to kep the height correct you might replace a 165 normal profile with a 185 60 series.
David
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Wow, more complex than it appears then. Not a simple width but a ratio. I'll have a closer look if it ever stops raining, and get back to you all.
Looks like the tyres are differnt diameters then !
The guy who I bought it off, had a full Volvo service history - all tyres having been replaced at the Volvo dealers.
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Alex,
You have two issues excluding MOT contraints. (If you look at the MOT checklist from your previous MOT, it may tell you if the spare is checked for compliance)
1
The ability to use the car in a normal manner and be safe doing it, using the standard size 4 wheels/tyres you have
2
The ability to get home after a puncture but allowing in your driving style the constraints of use your spare wheel imposes. This of course applies to all space saver type wheels, and I suggest, your own current spare as well. You will, of course, require to get the standard tyre repaired and refitted promptly.
Don't be influenced by cost and ignore safety, a repacement correctly sized tyre to suit your other 4 is not that expensive. I don't have the hard data that I am sure you would like, but it is almost certainly true that the fitting of assymetric tyre sizes on the same axle will influence adhesion and the cars normal driving character. This might catch you out in an emergency.
Regards,
Julian L
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Joules,
Thanks, about to go and look when it stops raining.
It's not a space saver wheel - its just the same as the others. Only on close inspection did I notice the different size. Clearly it was fitted in error at some time in the past. This model of Volvo does not use the space saver - when new all 5 tyres would have been the same.
Alex
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alex, the ideal, and if you are in a financial position to do so, fit two new tyres, and shove the 185 (now fixed, I hope) as the spare in the boot.
As the Volvo is a FWD, the two new ones should go on the front, and the old ones on the back.
if the pennies are a bit short, get the 185 fixed and fitted asap.
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Ian, Cape Town
It's rear well drive - a Volvo 900 series {last of the proper Volvos I hear you say?}. Cost not a problem, only £35 fitted and balanced {un - branded tyres }.
Or should I be buying £120 tyres - £600 to re-shod the whole car, thats prod worth £1500 tops {11 year old Volvo 940 ??????????}
Alex {Forest of Bowland, Lancs - centre of the UK and the Universe !!!!!!!! }
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stay with the 35 quid option! as long as they are kite-marked, and you don't thrash the thing, shouldn't be a problem.
stay with the new set on the front, though - better steering response.The other problem is that the 165 has been, by your own admission, in the boot for at least two years. Some folk fit the spare, which may be up to 10 years old , yet "brand new", and have horrific blow-outs as a result.
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Alex
1) The MOT does not cover the spare, only the tyres on the road. This has been discussed at length on the forum.
2) The 60 or 70 is the profile ratio ie the ratio of the 'height' of the tyre to the width.
3) It's not uncommon to have a spare tyre which is not a space saver which is different to the 'road tyres'. I have an Astra SXi, with 205/50 VR 16 road tyres. The factory spare is a 195/60 HR 15.
The handbook comment is it is designed for emergency use only, and 'may' affect handling. It should be replaced as soon as possible. I assume Vauxhall know the law and that it's legal. I don't know what would happen at an MOT though!
4) Unless your car's 165 spare has a different profile, then it will have a different diameter, and shouldn't be used long term. It could upset handling and if used on the back will make the diff work for its living.
Regards
John
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John S is right, the spare wheel is not a testable item - as long as it's not fitted as a roadwheel. Problem is, many spare wheels will be used as roadwheels at some time, and will be subject to the relevant regs.
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