Tyres i30

tweety · **April 06, 2016, 14:12:20**

I run 205/65R15 tyres and have done so for 150,000 of the 304,000km I've travelled.

I think from memory the original tyre was 185/65R15.

The 205/65R15 tyre and subsequent rim fits easily in the spare tyre wheel well.

The difference in circumference is a little over 4%. Meaning the wheel at 100kph turns 4% less so revs are 4% less also.

This results also in the speedo being more accurate according to VicRoads speed indicator signs and my calculations at the time using km roadside pegs.

The bonus is also 4% less rpm for a given speed ( say 100 rpm @ 100kph) , 4% better fuel economy ( I used to travel 60,000km a year = $ 160 a year savings) and 4% more kms out of your tyres (2000kms) and 20mm more rubber on the road (width). I'm not one that normally alters manufacturers spec but this one seems a win win win all round.

The new tyre size is a common size also.

CraigB · **Reply #1: April 06, 2016, 15:27:45**

You should have no difference in circumference as both tyres you've stated " 185 & 205 " are still 65 x 15, the only difference would be from the very slightly reduced circumference of the worn tread to the new tyre tread.

sundiz · **Reply #2: April 06, 2016, 16:50:42**

Quote from: CraigB on April 06, 2016, 15:27:45

You should have no difference in circumference as both tyres you've stated " 185 & 205 " are still 65 x 15, the only difference would be from the very slightly reduced circumference of the worn tread to the new tyre tread.

The height of the tyre is not same. The 65 is the % of side height divided by the width of the tyre. Therefore the height of the tyre with 185 width should be 120.25mm and with 205 width it should be 133.25. This height difference causes approx 4% change in the diameter of the tyre as tweety mentioned.

Surferdude · **Reply #3: April 06, 2016, 21:28:40**

Tweety, given that you say you had 185s originally, unlesss you've changed them, you have 5.5 inch wide rims.
If so, I'm pretty sure a 205 is an illegal fitment.
Far too much flex in the sidewall in an emergency.
that much extra width would possibly also magnify your wear problem.
A 205/65R15 needs a 6" rim minimum.
They seem to be working for you though. But insurance "might" be a problem.

Surferdude · **Reply #4: April 06, 2016, 21:29:31**

BTW. Sundiz is correct.

beerman · **Reply #5: April 06, 2016, 23:50:20**

I thought the original tyre on the i30 was 195? At least it was on my 2 FD i30s

diablo · **Reply #6: April 07, 2016, 01:24:35**

I just had to go out and check my tyre sizes as the report from my last service showed my new tyres as 215,55,16. Though they are 205,55,16 so same as old ones. Had me worried for a moment there.

Though those are 16 inch rims. The 15 inch ones were either 185 or 195 in the UK, I'd be a bit concerned about insurance claims if the tyre place had fitted 215s on my car.

tweety · **Reply #7: April 07, 2016, 01:42:03**

Guys my memory isn't good and it could be 195's as original.

Good point about insurance and tyre wear..

Surferdude · **Reply #8: April 07, 2016, 02:24:41**

185s were fitted in some markets, maybe the UK?
Mostly 195s in Oz but I sem to remember an occasional member saying they had 185s. Probably the earliest models.
Mine is 2009 and had 195s standard on 5.5 rims.

tweety · **Reply #9: April 07, 2016, 10:07:37**

VicRoads here in Victoria allow only 15% diameter increase of tyre from standard.

I read my tag insie my drivers door and it said tyres stockare 195/65R15

diameter of 195/65R15 = 634.5mm

diameter of 205/65R15 = 647.5mm difference = 13mm = legal.

Done a lot of reading on the net and 20mm wider with tyres isn't illegal as long as they don't scrape on any guards. The tyre doesn't look excessively wide compared to the rim and better protects wheel covers.

Tony

Surferdude · **Reply #10: April 07, 2016, 13:09:03**

Vehicle, tyre and wheel manufacturers adhere to the Australian Tyre and Rim Association manual.
So do state registration authorities, insurance companies and the Australian Design Rules.

As I said, they obviously work for you, but the legal aspect of fitting a tyre on a rim outside it's allowable rim range remains.

It's not a height isuue, nor a load or speed index issue. It's simply about the beads of the tyre, being too close together in relation to what it's designed for.

TBH, I'm surprised BJs went along with it, or at least, didn't mention it.

There are plenty of vehicles on the road with much more severe issue. But it would have been remiss of me not to have let you know.

And the extra width without the designed sidewall support would, definitely allow the tyre to distort enough, given the excessive camber, to accentuate the wear problem.

Can you confirm the actual camber figures for me?

Surferdude · **Reply #11: April 07, 2016, 13:13:27**

BTW, your first line above reads 15%. It should be 15mm as you've said further down.

Asterix · **Reply #12: April 07, 2016, 17:09:20**

My 2008 have a type approval with both 185/65-15 and 195/65-15 on 5,5" rims

Alternative sizes are 205/55-16 on 6" rims or 225/45-17 on 7" rims

sundiz · **Reply #13: April 07, 2016, 19:46:19**

I don't know if it is just me, but the 195/65-15 looks too much like donuts on the i30 stock rims. They look like toy or cartoon wheels. The rim could be wider. I had 7x15 rims with the same size tyre on other car. The tyres looked much better on 7 inch wide rims as the rim width was much closer to the width of the tyre.

Surferdude · **Reply #14: April 07, 2016, 21:43:37**

Quote from: sundiz on April 07, 2016, 19:46:19

I don't know if it is just me, but the 195/65-15 looks too much like donuts on the i30 stock rims. They look like toy or cartoon wheels. The rim could be wider. I had 7x15 rims with the same size tyre on other car. The tyres looked much better on 7 inch wide rims as the rim width was much closer to the width of the tyre.

There is such a thing as a "design rim size" applicable to every tyre size. For the 195/65R15 it is 6". It can legally be fitted to the rim range 5.5 tp 7.0 so your fitment is legal.
I'm away from home and only have my tablet hich is a pain to type on. Sometime over the next couple of days I'll start a thread explaining more fully the positive and negative effect of correct or incorrect rim and tyre fitment.

It's been difficult explaining to Tony (tweety) what I mean due to the limitations of the 7" tablet so, bear with me and I'll get back to you.

Trev

Dazzler · **Reply #15: April 08, 2016, 00:38:15**

Just a heads up to some of our newer members, Trevor had something like 35 years in the tyre industry including many years managing various Goodyear Service centres.

tweety · **Reply #16: April 08, 2016, 05:43:00**

While we wait for Trev to get that info here is the figures for the wheel alignment

Previous Final values

Front wheels LH RH LH RH

Camber -1.20' -00.20' -1.20' -00.30'

Castor +5.20 +5.30' +5.20 +5.30'

Rear Wheels

Camber -2.10' -1.00 +00.5' +00.5'

2.00 means 2 degrees. Havent got a little zero for the degrees on my keyboard. Cheers

Surferdude · **Reply #17: April 08, 2016, 08:51:38**

On a keyboard, try alt 0176
Should give you a °

tweety · **Reply #18: April 08, 2016, 10:18:34**

Didn't work but got onto google and copied and pasted. °

thanks surferdude

Surferdude · **Reply #19: April 11, 2016, 04:00:09**

Quote from: Surferdude on April 07, 2016, 21:43:37

Quote from: sundiz on April 07, 2016, 19:46:19
I don't know if it is just me, but the 195/65-15 looks too much like donuts on the i30 stock rims. They look like toy or cartoon wheels. The rim could be wider. I had 7x15 rims with the same size tyre on other car. The tyres looked much better on 7 inch wide rims as the rim width was much closer to the width of the tyre.

There is such a thing as a "design rim size" applicable to every tyre size. For the 195/65R15 it is 6". It can legally be fitted to the rim range 5.5 tp 7.0 so your fitment is legal.
I'm away from home and only have my tablet hich is a pain to type on. Sometime over the next couple of days I'll start a thread explaining more fully the positive and negative effect of correct or incorrect rim and tyre fitment.

It's been difficult explaining to Tony (tweety) what I mean due to the limitations of the 7" tablet so, bear with me and I'll get back to you.

Trev

OK guys. I haven't forgotten about this. I'm working on it.
Just back from 7 days of scrub clearing (including 30+ year old bougainvillea) on a 15' high bank along the front of my son's house in Brisbane. Give me another day or so.

rustynutz · **Reply #20: May 04, 2016, 03:21:09**

You recovered yet, Trev?

Surferdude · **Reply #21: May 04, 2016, 08:07:41**

Quote from: rustynutz on May 04, 2016, 03:21:09

You recovered yet, Trev?

Yep. Why?

rustynutz · **Reply #22: May 04, 2016, 12:08:59**

Well, 3 weeks ago you did say "give me another day or so"...

Surferdude · **Reply #23: May 04, 2016, 12:29:41**

Like this? I even stickied it.

TYRE AND RIM INFORMATION

Surferdude · **Reply #24: May 04, 2016, 12:33:28**

" Sometime over the next couple of days I'll start a thread explaining more fully the positive and negative effect of correct or incorrect rim and tyre fitment."

rustynutz · **Reply #25: May 04, 2016, 12:40:39**

Quote from: Surferdude on May 04, 2016, 12:29:41

Like this? I even stickied it.

TYRE AND RIM INFORMATION

Some kind of reference and a link to the stickied thread would have made that clear...

Surferdude · **Reply #26: May 04, 2016, 19:42:07**

What part of "I'll start a thread" did you have trouble with?