Tamora tyre rating

[paul1962]

Hi,

It's time for some new tyres on the front of the Tamora.

Looking at whats fitted at the moment I'm a little confused.
Rears are R18 95Y
Fronts are ZR18 83W

I thought they should be ZR18 all round shouldn't they ?
Can anyone clarify what should be fitted ?

Thinking of Goodyear as that's what's on the rear and I like them but can't find any ZR rated anywhere. One place when asked to clarify they'd be providing ZR said they'd be R1895Y.

Any help much appreciated - I'm confused!

Paul

[kevin63]

There's some usful info on here Paul http://www.blackcircles.com/general/speedrating

[TA14]

Hi Paul, all of the tyres that you mentioned are Z rated; that is for speeds in excess of 150mph. To keep costs down two sub-classes of Z have been created: W up to 168mph and Y up to 186mph. The 83 and 95 are load ratings; I'm surprised that you may need over 91, what does the handbook say?

[TVR_owner]

Paul there are very few people that we would drag ourselves from a comfortable chair for....

The brides wee red thing wears Eagle F1 as were fitted to her car when new.

225x35 ZR18 87Y

235x40 ZR18 91Y

Temp, traction and wear same front and rear.

Hope this helps?

Edited by TVR_owner on Sunday 3rd February 20:57

[paul1962]

Thanks for the replies everyone.

Hope you're back in your comfy chair now John

It was the missing 'Z' before the 'R' on the rears which confused me but it looks like they're higher speed rating than the fronts.
Anyone know the reason for the first 'Z' and why it appears on some tyres and not others ?

TA18, the book just says 225/35 ZR18.

Will have another search later today.

Thanks
Paul

[Sevenman]

As the car has a quoted top speed of > 168mph, there is a case for having Y-rated tyres, which is what the cars were supplied with.

Not sure if a stock Tamora can go that quickly. I haven't tried.

I would not have thought that the use of W-rated tyres, which are good to 168mph, would be a particular problem or cause insurance issues.

I am surprised your fronts are 83 load rating (487kg), rather than the 87 (545kg) that seems more common for that tyre size. What sort of tyres are they?

Again, I don't think that would be an issue as the car is well within the load rating - my Tamora has ~ 300kg on the front corners depending on how the car is loaded.

It would be worth buying fronts to match the rears. How old are the rear tyres? There should be a 4-digit code on the sidewall, for example "3510", for week 35 of 2010. If the tyres are quite old, you might not be able to find fronts to match exactly.

[TVR_owner]

Why do you suggest the cars dud not come with z rated 18" tyres from new?

[paul1962]

I guess it's times like this I wish I'd checked what was on the car when I bought it...

Rears 235/40/R18/95Y : Goodyear F1 dated 3011 (Nearside), 4608 (offside). Near side is the newer F1 Asymmetric, offside isn't
Obviously more wear on the older tyre but not much.

Fronts are Federal, 225/35/ZR18/83W. Didn't check year code but one needs replacing so will obviously replace both.

So, for some reason quite a mix fitted before I bought it.

From another site : R18-83Y Vehicles not exceeding 300kph, ZR18-83Y Vehicles capable of over 240kph but not exceeding 300kph. No idea what the real difference is.

Question : What to do with the rears ?

Edited by paul1962 on Monday 4th February 13:35

[Sevenman]

TVR_owner said:

Why do you suggest the cars did not come with z rated 18" tyres from new?

Was that addressed to me?

They would have come with Z-rated tyres. But probably Z-Y tyres rather than Z-W

So as you said:

TVR_owner said:

225x35 ZR18 87Y

235x40 ZR18 91Y

matches my understanding of the standard tyres.

The rears often seem to come in 95 load rating as well as 91. Shouldn't make much difference.

paul1962 said:

I guess it's times like this I wish I'd checked what was on the car when I bought it...

Rears 235/40/R18/95Y : Goodyear F1 dated 3011 (Nearside), 4608 (offside). Near side is the newer F1 Asymmetric, offside isn't
Obviously more wear on the older tyre but not much.

I changed the tyres on my Tamora a few months after I bought it. There were in good condition with plenty of tread but dated from when the car was new (2002/2003 tyres). It only had 13,500 miles so the tyres hadn't worn much, but that is too long to keep tyres on a performance car.

Given the changes in the Eagle F1 between 2008 and 2011 it looks like you are effectively running different tyres across the rear axle of your car, which is generally not recommended. I wouldn't know how critical this is, I guess it depends on how much difference the compounds / tread patterns / age make.

[TVR_owner]

Sevenman said:

TVR_owner said:

Why do you suggest the cars did not come with z rated 18" tyres from new?

Was that addressed to me?

They would have come with Z-rated tyres. But probably Z-Y tyres rather than Z-W

So as you said:

TVR_owner said:

225x35 ZR18 87Y

235x40 ZR18 91Y

Apologies Gavin, didn't read the answer correctly. Are happy with your car now (brakes etc?)

[Sevenman]

TVR_owner said:

Apologies Gavin, didn't read the answer correctly. Are happy with your car now (brakes etc?)

No worries. I think the brakes may now be sorted following the replacement of front and rear pads with the correct Ferodo DS2500 compounds, but I really need to do some on-track testing.

Suspension will be having a full geo soon (will post before / after setup details on the forum) and rear spring rates will most likely go up from 325, not sure how high yet (front is 400).

With a nod to keeping the thread on track, the tyres, Toyo T1-Sport, (Y-rated) have been doing very well for spirited road driving in varied conditions.

[SeiW500]

Rears 235/40/R18/95Y : Goodyear F1 dated 3011 (Nearside), 4608 (offside). Near side is the newer F1 Asymmetric, offside isn't
Obviously more wear on the older tyre but not much.

If it were me i'd want the same tyre type on each corner & i'd definitely NOT have different tyres on the same axle!
After doing some research Goodyear Eagle F1 Asymmetric 2 would be my choice....

[shep1001]

paul1962 said:

Hi,

It's time for some new tyres on the front of the Tamora.

Looking at whats fitted at the moment I'm a little confused.
Rears are R18 95Y
Fronts are ZR18 83W

I thought they should be ZR18 all round shouldn't they ?
Can anyone clarify what should be fitted ?

Thinking of Goodyear as that's what's on the rear and I like them but can't find any ZR rated anywhere. One place when asked to clarify they'd be providing ZR said they'd be R1895Y.

Any help much appreciated - I'm confused!

Paul

Paul if you go with the Goodyear tyre, Camskill are the cheapest (that I found) at £132 + delivery of £3/tyre. They also have an additional £10 cash back per tyre on top of this through Goodyear's winter tyre promotion.


Shep

[paul1962]

shep1001 said:

Paul if you go with the Goodyear tyre, Camskill are the cheapest (that I found) at £132 + delivery of £3/tyre. They also have an additional £10 cash back per tyre on top of this through Goodyear's winter tyre promotion.


Shep

Unfortunately no stock for the 'Y' and they don't know when they'll be getting more.
Still checking other sources.

[TA14]

paul1962 said:

Unfortunately no stock for the 'Y' and they don't know when they'll be getting more.
Still checking other sources.

Mytyres come in at £147. Time to see how close your local supplier can get?