The Tyre Thread

[Lauren 2259]

4 hours ago, Subota Boy said:

Interested to know, does a 225/45 not work as well as a 215/45 on the standard rim?  Any advice/opinion appreciated.

No, 225 is too wide for the meagre 7" rim. Will result in a taller sidewall due to the increased width proportional to the profile which will make it worse. Don't do it. 

Wear wise, I go through three sets of rears to one set of fronts. So 7K for the rears and 21K or so for the fronts. I don't rotate my tyres. 

[Mike 458]

3 hours ago, Rich said:

Had my Advans on for just over 10k miles now. Around 4mm left all round (marginally less at the rear than front). Very pleased with the wear rate, seems I'm easy on the tyres.

I pretty much went through a set of fronts in ~14k  

[Lauren 2259]

1 hour ago, Mike said:

I pretty much went through a set of fronts in ~14k  

It must be your driving styles. 

I do appear to be light on everything apart from rear tyres for some reason.

[Subota Boy 402]

Thanks to everyone for your advice.  Much appreciated!  

[KevinA 695]

I am making no choices until the MSA 2017 lists are out, as I do very few road miles and need to decide on next year's TSS class.

[Rich 378]

12 hours ago, Lauren said:

It must be your driving styles. 

I do appear to be light on everything apart from rear tyres for some reason.

Must be all those burnouts.

[TTR 509]

Just a quick question for those that are on 18" wheels. 35 or 40 tyre profile? 

[Paul 442]

225/40/18.

[KevinA 695]

40 up to 235 then 35 after that.

[Ade 517]

Just now, KevinA said:

40 up to 235 then 35 after that.

Im running 235/40 stretched on a 9J rim. 3% faster so the speedo will be spot on. 

AD08R are wide for a 235 though.

Will go for 245/35 if I decide to go for CUP 2s

[TTR 509]

Is anybody running on 245/40/18? Really want Pilot Sport 4's, but they don't come in a 245/35/18 fitment  

[S18 RSG 429]

24 minutes ago, TTR said:

Is anybody running on 245/40/18? Really want Pilot Sport 4's, but they don't come in a 245/35/18 fitment  

That's gonna throw your speedo off by some way. I'm having the same problem currently, as I want PS4's in that size. I'm either gonna go 235/40s or 245/35 AD08R's or something.

[TTR 509]

6 minutes ago, S18 RSG said:

That's gonna throw your speedo off by some way. I'm having the same problem currently, as I want PS4's in that size. I'm either gonna go 235/40s or 245/35 AD08R's or something.

Throw it off? It under-reads anyway. So I usually go by GPS speed on my headunit and then just work from there on the tacho.

Problem for me is, I'm on 9.5" wide rims and don't really want the stretch that comes with the 235 and the 255's that are on there at the moment are just a tad too big haha.

[S18 RSG 429]

3 minutes ago, TTR said:

Throw it off? It under-reads anyway. So I usually go by GPS speed on my headunit and then just work from there on the tacho.

Problem for me is, I'm on 9.5" wide rims and don't really want the stretch that comes with the 235 and the 255's that are on there at the moment are just a tad too big haha.

Comparing to stock sizes, that tyre will under-read the speedo by almost 6%, that's quite significant. I don't know what sizes you have currently, but I'm assuming 255/35. Your current setup under-reads the speedo by almost 3%, and going to 245/40 will make it a further 3% worse, not fix it. Use this for reference http://www.willtheyfit.com/index.php?width=255&aspect=35&diameter=18&wheelwidth=9.5&offset=40&width2=245&aspect2=40&wheel_size=18&wheel_width=9-5&offset2=40

Going to a 245/35 will correct your speedo error by a little over 1%, which takes it closer to stock. Might be worth looking at other tyres in the correct size rather than the right tyre in the wrong size.

[Lauren 2259]

49 minutes ago, TTR said:

Is anybody running on 245/40/18? Really want Pilot Sport 4's, but they don't come in a 245/35/18 fitment  

Big sidewalls, will flex a fair bit. As other's have said, get a different tyre in a better size. It seems like PS4's are the latest must have for some reason. 

[TTR 509]

9 minutes ago, S18 RSG said:

Comparing to stock sizes, that tyre will under-read the speedo by almost 6%, that's quite significant. I don't know what sizes you have currently, but I'm assuming 255/35. Your current setup under-reads the speedo by almost 3%, and going to 245/40 will make it a further 3% worse, not fix it. Use this for reference http://www.willtheyfit.com/index.php?width=255&aspect=35&diameter=18&wheelwidth=9.5&offset=40&width2=245&aspect2=40&wheel_size=18&wheel_width=9-5&offset2=40

Going to a 245/35 will correct your speedo error by a little over 1%, which takes it closer to stock. Might be worth looking at other tyres in the correct size rather than the right tyre in the wrong size.

The speedo error I had stock was about 10%. Would read 77, with 70 on GPS. So, going to 245/40 would make it 3% worse than what I currently have, but still not as bad as stock. I'm not really sure whether the issue you're getting is actually that fucking important for when I'm pushing on 

My concern is the amount of sidewall on a 245/40/18, is the sidewall/diameter/circumference increase going to be an issue and has anybody with experience of said tyre fitment got any comments to make vs what i'm currently on.

[TTR 509]

3 minutes ago, Lauren said:

Big sidewalls, will flex a fair bit. As other's have said, get a different tyre in a better size. It seems like PS4's are the latest must have for some reason. 

Thank you for answering the concern that I had Lauren, much appreciated 

[Lauren 2259]

1 minute ago, TTR said:

My concern is the amount of sidewall on a 245/40/18, is the sidewall/diameter/circumference increase going to be an issue and has anybody with experience of said tyre fitment got any comments to make vs what i'm currently on.

It'll be shite. I've driven a GT86 with this size tyre on track. Not good. 

[TTR 509]

Just now, Lauren said:

It'll be shite. I've driven a GT86 with this size tyre on track. Not good. 

As previously said, thank you for actually providing the information I was after 

[S18 RSG 429]

11 minutes ago, TTR said:

As previously said, thank you for actually providing the information I was after 

Here's a tip. Rather than being a dick when someone gives you an answer you weren't interested in, maybe be a little more concise when you ask the fucking question. 

Your question didn't mention you were "concerned about size of sidewall", and my answer didn't mention that as I have no experience of that issue, I just gave you information perfectly relevant to your question that I could find to help you out. Remind me not to bother wasting my time on you again.

[TTR 509]

1 minute ago, S18 RSG said:

Here's a tip. Rather than being a dick when someone gives you an answer you weren't interested in, maybe be a little more concise when you ask the fucking question. 

Your question didn't mention you were "concerned about size of sidewall", and my answer didn't mention that as I have no experience of that issue, I just gave you information perfectly relevant to your question that I could find to help you out. Remind me not to bother wasting my time on you again.

How was I being a dick? There was no malice in my comments 

Pretty sure the below would give off the indication that what you mentioned wasn't relevant to my question. But anyway, no malice in my comments.

36 minutes ago, TTR said:

Throw it off? It under-reads anyway. So I usually go by GPS speed on my headunit and then just work from there on the tacho.

Below is another indication that my question was about sidewall, highlighted in bold.

1 hour ago, TTR said:

Is anybody running on 245/40/18? Really want Pilot Sport 4's, but they don't come in a 245/35/18 fitment  

Don't be so quick to take offence on the internet bud, Lauren got my concern first try 

[S18 RSG 429]

Your question was about tyre sizes, not sidewalls. If you wanted to ask a question about sidewalls, you'd have asked "Will the sidewall be too large on a 245/40?", or "Will the car drive poorly on 245/40?". You didn't. You asked a general question about tyres and I gave you a general concern.

Lauren answered your question in the way you "wanted" because her first consideration when answering questions is usually "How will this issue effect how the car drives?". I don't have that knowledge as I've not driven any car other than my own in anger, and I'm not gonna guess just to be helpful, but I wanted to be helpful. I know that one reason people stick to certain tyre sizes in general, is to keep speedo readings fairly accurate. Ok, that's not a concern to you, but my name is Ross, not mystic Meg, so there's no way for me to know that.

Also, I'll never take offence to anything you say to or about me, don't flatter yourself

[KevinA 695]

It's all down to personal preference and your driving style, I run wide tyres on wide rims without any problems. Not quicker or slower but feels how I like it, try different combinations if you have the chance and settle for what feels right.

[TTR 509]

So I think I've settled on Goodyear F1 Asymmetric 3's in either 245/35/18 or 255/35/18

[Lauren 2259]

I admit, I haven't tried the current F1's though in a way I have, driving Keith's turbo GT on track with 245's. F1s tend to be soft on the sidewall and don't tend to take track abuse well. Great for the road though, probably.