takahashi

Good info dbb

I think Toyo is a bit underrated in that though... I think they worth more than 4.1 if Pilot Sport get 4.8 (or if I mistaken PS2 is the "cup" version in Australia ~ i.e. semislick?)

Gomez

Ooooh, just spotted this......don't rely on the overhead speed check gantrys in Victoria to be accurate. They are notoriously innaccurate at times. The best (cheapest) way to accurately check your speedo remains the tried and true timed run over a marked kilometre. I reckon the digital jobbie in the 8 is pretty good actually......

Regards, Gomez.

takahashi

How about the GPS system that calculate the speed - any less of the error there!?

I agree with Gomez though, old method is a good method. :o

timbo

Because I must be an anally retentive sort of guy , and keep driving back and forth between Canberra and Sydney, I do the marked 5K tests a lot, and consistently find my speedo reads about 5% high :o

Lock & Load

Timbo

This is Mazda way of making us feel that we actually driving a faster car , I HAVE ALWAYS FELT THAT THE SPEEDO IS NOT VERY ACCURATE , very much on the high side .
5% SHAME MAZDA SHAME .

cheers
michael

rotarenvy

you reckon it's that bad? when I'm on the highway with it set to 100km/h I seem to be at the same speed as other cars. at 5% ie 5km/h you would get overtaken by everyone very quickly.

timbo

Actually, I must correct myself. The odometer reads 5% high. Whether that translates to the speedo is another issue.

But, reading most car tests these days, which use Correvit timing gear, a 5% error seems about the norm

Spazm

I was doing a search for tire sizing, and inside one of those I was linked to this thread...I was wondering why everyone posting was from Aus, until I saw what forum I was in :D Guess I'm out of my turf.

But if you wouldn't mind, I wanted to ask a question. I read through the entire thread, and saw no information on 19" wheels. I did want to go 19", but the tire selection seems to be limited.

What I feel to be my best bet are Falken GR Beta FK-451, in 235/35ZR-19. What would be the pros/cons of these kinds of tires? I also plan to lower the car ~1" with a MS suspension, so I want to minimize rubbing. However, I also don't want to be riding on a super-low profile tire.

Thanks for any input.

EDIT: Oh, and if any of this looks like I don't know what I'm talking about, that is absolutely correct.

timbo

Everything is relative, as they say :p

AFAIK, 19" means you must go for a fairly low profile tyre to avoid fouling. A 235/35 has a sidewall size of 87mm compared to the stock 225/45 - 18 tyre sidewall of 101mm. That means it's 14% 'thinner' if that is your concern re lower profile, with all the additional harshness that implies. If you also lower the suspension, I don't think you can expect any compensating benefit

It's not something I'd do, especially if I had any comfort concerns.

rotarenvy

the limited tyre range is one reason I'm not going 19".
other reasons; the lower side wall height reduces ride quality, rough road handling; while you can find light weigh 19" wheels, a light 19" weighs more than a light weight 18".
19" look good tho

pepe

Anyone in Aus replaced the stockers after wearing them out? Did a call around today, here's the results in CBR... will go to Syd if prices are worth it and I can get it done in a few hours while I'm there.

Bridgestone RE040 : $420 - $510
Bridgestone GIII : $340 - $374
Michelin Pilot Sport : $535 - $685
Falken ZE512 : $452 - $600
Pirelli ZeroRossi : $530

These are all the stock size, got various quotes on 245/40R18s, but keen to stick to the stock size... had more than one place say "are you sitting down?" when they came back with the prices, many of them said it's a very uncommon size and would be very very pricey...

Advice anyone? Need to purchase in the next few weeks (on the wear bars already)

Anyone heard anything about the Bridgestone G3s (GIII) ? Apparently they're new here, hard to find much info.

Oh, and if you look at the Bridgestone Aus website, unless you put in the RX-8, they don't list the RE040 as available anymore, calling them direct today, apparently they only have 4 left in the country (not kidding you, enough for one car!)

timbo

pepe

I have found the same thing (and yes, I know I was supposed to compile a sticky on this, but it is quite depressing). Might check out Sydney prices next time I am there.

And there are other problems: two weeks ago I was told there are no Bridgestone RE040s in the country and it was not known when they were due. A bit of a problem if you rip one tyre.

I'd add to your list

Yokohama V102 $460
Yokohama V141 $530
Yokohama ES100 $410 (on a par with the 040s)

There is more choice in 245/40-18, they are legal and I have a verbal ok from my insurer, but I'm unsure if they might not foul at the front.

What about 225/45s on the fron and 245/40s on the rear .... or is that possibly a bit naff??

Perhaps we could try a bulk buy, at least in Canberra -- 8 tyres not being very 'bulk'

takahashi

How about the Potenza S03s.. I think they are in 245/40-18 only..

I will go to 245/40-18. They might be cheaper than you think coz the HSVs and now the FPVs are in this size

Ageo

When i punctured my tire i had a temp tyre which was fitted. The size is at 225/40 which is fitted on the rear left side. so i have 3 tyres in at 225/45 and 1 at 225/40. I need to do a wheel alignment and balance but do you guys think it will be ok for the time being? because i am hearing a noise when i turn at the front (knocking noise). Or do you guys think alot of wearing will happen because of it.

takahashi

this is weird! You can't find 225/45-18. I will give the bill to Mazda Australia asking why no 225/5-18. They should pay the difference to change the other 3 tyre to match size

That is, I doubt it is good at all to run cars with different size... let alone left is different to right!

labrat

OK, I just rang Quick Fit Tyre service. You can get a Kumho 225/40 R18 92W for $329.00. They load rating is slightly above the 91W for the stock Bridgestone. They say that they have got excellent customer feedback from this tyre, good tread wear, performance, and quiet, too.

I went to www.tirerack.com, checked over what was available in 225/40 18's, and then tracked down the AU websites to see what sort of product match I could find.

pepe

According to this site : http://www.1010tires.com/TireSizeCalculator.asp

The diff in size is 3.43% when going with a 225/40R18, that's a sizeable diff... the diff with a 245/40R18 is only 1%, which is acceptable. I'm not going to risk the 225/40s, have found plenty of 225/45s and 245/40s, but all rather pricey... looking at a set of Falkens for $395 fitted, just trying to find out whether they're any good.

takahashi

....eh labrat... I hate to do this and waste your effort....

225/45-18 is the size I think. I am pretty sure.

labrat

oops, you're right. Back to the drawing board

labrat

OK, in 245/40R18's in Kumho you have:

Ecsta 712, load rating 93W = $328
Ecsta KU19, load rating 97W = $349

Check out www.kumho.com.au

takahashi

Not bad for that price

How about the Y rated The Kumho ECSTA KU15 MX which is "an ultra high performance tyre and can be used on the track as well as on the road by motoring enthusiasts."

Jellybean

Saw a nice looking set of Made in Japan 235/40R18 Firestone Fire Hawks in my local Bridgestone Belconnen store for $299 a corner. Now, to quote Pepe, "just trying to find out whether they're any good".

labrat

I guess whether you fit 235/40R18's comes down to whether you accept the inherent errors in your odometer/speedometer reading(s). 245/40R18's will give practically zero error over the stock 225/45R18's.

takahashi

Hey I found this Labrat that may be helpful

Tire calculator

This is what I get for differenent sizes

Specification Sidewall Radius Diameter Circumference Revs/km Difference
225/45-18 101mm 330mm 660mm 2073mm 483 0.0%
235/40-18 94mm 323mm 645mm 2027mm 493 -2.2%
245/40-18 98mm 327mm 653mm 2052mm 487 -1.0%
255/40-18 102mm 331mm 661mm 2077mm 481 0.2%

Sorry that I can't line it up nicely as a table.. stupid forum

Apparently the closest is 255/40-18. But for some strange law that we cannot upsize the tyre *can someone confirm that?*. The closest we can get 245/40-18 with -1% difference.

timbo

My understanding is you must
(a) meet tyre placard weight and speed rating
(b) meet the wheel rim/tyre width rating (and 245 is the max for 8" rim, ruling out 255/40)
(c) be within 10mm diameter of original spec; and
(d) must not affect speedo by more than 10% under the ADRs and various state registration authority interpretations of these.
Separate to this is how your insurance company views and modification. I have a 'verbal' from AAMI that 245/40-18 would be ok given the limited supply/choice of of 225/45-18s around. Three tyre shops said 235/40 are below the tolerance but I don't see how that could be