:p - sounds like that involves common sense to me.

Anyway - a pair of Toyos should be delivered to my work today and I have the 2 wheels on my back seat, so I should be back on 4 alloys by the end of the day!

Firstly the x/40 or x/60 is the aspect ratio ( % of the width ie 40% of 205mm) NOT mm. Working this out it means that the 205/40 17 has a diameter of 595.4mm and the 185/60 14 has diameter of 577.6. Now converting this into a rolling circumference you get 1870mm approx for the 17inch combo and 1814mm approx for the 14inch combo. This means for the same number of turns of the wheel the 17inch combo will travel aproximately 10% further so your speedo is UNDER reading by 10% and your mileage :). Just watch the speed cameras!!!!

Just watch the speed cameras!!!!

Coupled with the mysterious over-reading VAG speedos, it'll probably make it about right then...

I guess 205/35s would've been the ones to go for...

Rob.

I'm not sure it's 10% - and it's too late telling me about speed cameras.... :(

I was just wondering if the steels are actually wrapped by 185/65 R14, 185/60s... But I honestly can't remember off the top of my head, and I can't be ar5ed to go out to the car park to have a look.

Well, as I have a pair of steels on the front now, I was doing what my speedo said was 60mph on an a-road, and I could have sworn I was only driving at 55... Perhaps 10% is about right. for the mileage saved.

As it happens, an online routeplanner, which I assume is very accurate said Duxford was 240 miles from my house, and the trip was 245 miles, with no detours off the route. To me, this suggests my speedo could be reading dead accurate now... Better go through all cameras at the limit or less, eh?

Better go through all cameras at the limit or less, eh?

Invest in a GPS device which tells you your real speed. Go on, spend some more money...

Rob.

Rob

My best chance is on the 12th - I'm also assuming that Jabba's rolling road is dead accurate, so I'll request while they're doing any dyno tests whether they can just check the readout on the road, vs, the speedo readout...

GPS? err, no.

Funny someone should mention gps. I have a system that runs on my laptop and gives me voice navigation, which is pretty good as long as the options are more than 100m apart and you watch it carefully on slips and rounabouts as it measures from the exit not entrance. Pretty good for

My best chance is on the 12th - I'm also assuming that Jabba's rolling road is dead accurate' date=' so I'll request while they're doing any dyno tests whether they can just check the readout on the road, vs, the speedo readout...

[/quote']

Yeah, I see no reason why they shouldn't be able to check it.

Just chucked the figured into the calculator webpage Denis refers to above - according to that you'll now be doing 73mph when your speedo says 70. However, in the likely event that the speedo is out anyway, then when your speedo says 70 you'll be doing about 68 now instead of 65.

Rob.

Yep - Rob - My initial difference I was told was something like 3% which is what surprised me when I looked at the wheels on my car, and how the steel looked smaller?

Could this be the ultimate ad for 17s with 205/40 tyres? - It'll mean your next service will come up further away - retain value as the car will have less miles on it at selling point. etc etc. (it does cause the mpg on the computer to read higher though. :()

Hmmm. I thought mytyres did a next day delivery, but the order tracking says mine aren't going to arrive until the 9/12/03! :eek:

This is cutting things bloody fine with my trip to Jabba and the Derby meet - if they arrive any later than the 10th I'm left in a real lurch! :( (sent an email wondering why they promise next day delivery but mine are taking a week...)

Only small thing I can think of is I'm a new customer and they want to verify my details before sending me my rubber.... Noooo, I need them nooooowwwww!

Imagine having to wait that long for rubber. You'd just go off the whole idea wouldn't you?

Yes - but unfortunately I don't have a couple of Toyo 205/40s in my wallet! :(

Ive just had a disturbing thought, this was on the inside of the tyre, are you show when on lock its not catching on something which induced a fatal flaw.......

I'm positive it's not that Andy, but thanks for the thought. It was high enough on the shoulder to be something I ran over on the road which may have started it off. I'm still going with my mate's drive which has had a sectioned of mud filled in with stones, some sharp looking too...

It still doesn't excuse the way the tyre fell to bits though!

BTW - I (and ATS too actually) checked for clearance around the tyre when I got the alloys fitted. There's a small, but big enough gap between the wheel and the suspension strut/spring, and on full lock to lock it never came close to rubbing any arches or similar. I think I'd need to drop it another 40mm or more to start getting into that territory.

:cheers:

Ah, the small print

Jason, did your tyres have *** against them (I imagine they did due to their size/speed rating)? It say allow 7-10 days for delivery IIRC.

Mine said that and they in 3 days, so you should be OK. All else fails, give Protyre a ring and they'll do them next day for you

Oh, and I still reckon its rubbing due to the way its peeled

Firstly the x/40 or x/60 is the aspect ratio ( % of the width ie 40% of 205mm) NOT mm. Working this out it means that the 205/40 17 has a diameter of 595.4mm and the 185/60 14 has diameter of 577.6. Now converting this into a rolling circumference you get 1870mm approx for the 17inch combo and 1814mm approx for the 14inch combo. This means for the same number of turns of the wheel the 17inch combo will travel aproximately 10% further so your speedo is UNDER reading by 10% and your mileage :). Just watch the speed cameras!!!!

Erm, I think you need to book your calculator in for a service. The difference is only 3% - ((1870 - 1814) / 1814) * 100 = 3.08% - well within the tolerance of the speedo, and as (accurately) quoted when the wheels were fitted.

Oh, and there's no need to work out the circumference - we are talking proportions here, so the constant scaling factor of 2xPI cancels - using the diameter is also more accurate as PI is not a rational number...

Oh' date=' and I still reckon its rubbing due to the way its peeled [/quote']

Looks more like they've been run under inflated to me. Only takes a few miles at speed with the tyres down by a few PSI to damage the structure of low profile tyres quite severely. I always keep mine at the upper-end of the suggested figures (i.e. heavy load &/or high speed).

Hmm -I'd go for the low pressure option - rubbing just can't happen unless it's at the extremes of the suspension travelor something... :confused:

(It took me two days of running my steels on the front to find out both were at about 18psi :eek: - Q is what is a good pressure for a 205/40? 0 I may as well start off with the Toyos the way I mean to go on)

Oh,and Jon - There telephone people said that the Toyos have to come all the way from Sauerkraut land, and will be with me by the 9th, at the VERY LATEST (they said) - so all should be fine.

Dunno the right pressure for a Furby, but the 215/40/17's on my MINI were 36 all round, and the cars are similar weight. Would seem like a good place to start.

(Whohoo! Thats 50 posts...)

36? That about 5 psi more than I was running in my Marshalls. They were normally in the 31 - 32 psi range. If anyone else is running their tyres at around 35 psi, then I will too, when I (eventually) get my new tyres.

Range for the tyres was 32 for normal speed & loads, and 36 for high speed or fully laden (i.e. 3 or more people). So seeing as I didn't fancy pumping the tyres up every time I went a little bit faster or took a few mates for a spin, I kept them at 36. Improved the ride, too - took away some bounce...

Toyo's arrived from mytyres at my Exeter office this afternoon. - So, I can actually take my alloys to work tomorrow and get them on the car. wahoo!

PS: anyone got any good comments I should make toward ATS about the way the tyre's failed - just wondering if I can push my luck and try and get something out of them?

Toyos on the alloys, on the car, and I'm dead chuffed! I'm not going to push it hard though until Derby meet as the rubber is still quite fresh and will need some bedding in before any small risks are taken.