Oh no! Another tyre question. More of a technical question though.

Firegod · 5 Jan 2008 at 14:45

Hello!

I'm looking to upgrade my tyres on the ST to Goodyear Eagle F1 GSD3's. I've read on the internet that you can safely oversize the tyres by 20mm, so I have looked at a slightly wider, 215 profile (10mm bigger).

My std. size is 205/40/R17. The price of the tyre for this size is £89.10 per corner.

Yet, the 215/40/R17 price is £82.50 per corner! Wow, cheaper and slightly fatter looking tyre.

Just wanted to check really if this is an ok thing to do really, I've read threads on owners clubs, etc where people have done this and not noticed any problems.

The technical question....

EAGLE F1 GS-D3 215/40 ZR17 83Y BSW

Now the parts I can understand are:-

1. The name - EAGLE F1 GS-D3
2. 215/40/R17 - The size
3. 83 - The load rating
4. Y - The speed rating
5. BSW - "Black Side Wall"

But what is the "Z" part in ZR17???

Cheers for the help.

Firegod · 5 Jan 2008 at 16:32

zain said:
At a guess I would say Zero, that's what mine stand for.

This means it has quite high speed limits something like 150 or 160.

If you're confident change the tyres, I would stick with standard.

Cheers for the help.

Firegod · 5 Jan 2008 at 17:05

Thanks guys.

Dandle, never thought about the insurance. Will check that out!

Firegod · 6 Jan 2008 at 13:19

Cheers everyone, some useful replies!

Think I'm going to go for it... well not till payday. lol.

Firegod · 6 Jan 2008 at 18:32

Jamous said:
Which ST?? At that size, can't be Focus ST (18's), ST24(16's) or 200(215/45R17), so I'm guessing Fiesta? assuming std wheels.
Worth noting is that the extra width may cause the tyre to rub on arches or suspension, have a look to see how close your are at the moment.
I'd do it for the extra grip you gain.

Aye Fez ST mate. Just running std. suspension so there's plenty of room.

I'm going to do it as well.

divine` said:
"Prior to 1991, tire speed ratings were shown inside the tire size, replacing the "R" character. The available codes were SR (112 mph, 180km/h), HR (130 mph, 210 km/h), VR (in excess of 130 mph, 210 km/h) and ZR (in excess of 149 mph, 270 km/h). The ZR code is still in common use, often combined with a W or Y speed code."

Ahhhh so it's just the speed rating afterall. Excellent, thanks for that.