Can I fit a smaller width tyre on the rim

[TransAmDan]

Well I need to buy a pair of front tyres. My size is 275/40/17. The tyres start at ?159 each.
However by changing the width, i get to see cheaper tyres. I spotted some bargain ones of 255/40/17 , for ?70 each. Now they are probably rubbish in the wet, however looking at an independent tyre test result, they are similar to Michelin, although not as good as the Falkens I currently have.

So my question is. Can I fit a 20mm less width tyre on the rim? i know I could probably get away with 10mm difference with no issues.

 

[Darren]

It's not just the width that alters, which is the problem:

Tyre size	275/40r17	255/40r17
Width	27.50cm	25.50cm
Sidewall Height	11.00cm	10.20cm
Radius	32.59cm	31.79cm
Circumference	204.77cm	199.74cm
Speedo / Actual	60mph	58.5mph

I'd say that 20mm too small is a big difference, they'll end up looking like stretched euro style wheels, but if you had to go 255, I'd up the sidewall to 45% (255/45r17) which is closer to the original circumference (207.75cm and 60.9 mph) than the 255/40.

The speed doesn't really matter to you as it's the front tyres, but I still think the stretch would be too much.

 

[TransAmDan]

Thanks for that Darren. Thats some great info there.

 

[TransAmDan]

This is the state of my front tyres after 6000 miles.

The 6000 miles started when Denmead tyres changed the tyres and I paid ?80 for full tracking to be done including camber adjustments to save me money in tyres in the long run, as they would look tread on the inner edge after 10000 miles. Looks like the adjustment was made the wrong way and they are lasting even less time. So there goes another ?320 on a pair of tyres. Naturally you would think i would get though more rear tyres :burnout:

80% of the tyre almost looks as good as new. Its a shame they have gone so quick. I know I should have checked more often as this could have been dangerous and go bang at any time. I'm gonna take both front off and take them down in the Fiesta to get changed, then put them on the car and drive to somewhere to get tracking looked at.

Tracking places? Did someone mention on in Farlington?

 

[Darren]

That's definitely not right. I'll see if I can find out anywhere for tracking.

 

[Darren]

Try The Wheel Alignment Center in Southampton, opposite to Ikea. He charges ?50, and sometimes ?40 cash-in-hand if you've been before. Superb guy.

The Wheel Alignment Centre

Read more: Hashiriya Shows - Login

 

[saleen 192]

got mine done at discount tyres worthing had to make a few adjustments and reballence two tyres ?140 from memory was about 3 hours intotal

Discount Tyre Direct - Performance Tyre and Computer Geometry Alignment Specialist

They have the hunter system so should have the spec for your car have used them a few times over the years very good service


Update found the mocgb link i did hope it helps?

whitch rolling road to use advice please - Page 2

 

[TransAmDan]

New tyres have arrived. I will get them fitted tomorrow. yay.