tyre size

[mathew_colville]

Hey ive just put some 15's i had laying around on my car as the pot holes on the dirt road are getting quiet bad after the rain, the tyres are 205/60/15
my question is, are these ok to use or are they to big?

the way i read it is that the gsr came with 195/60r14 and the evo came with the below sizes?

Manufacturer Overall Outside Diameter measurements as per tyre placards on Lancer Evolution
195/65/15 = 634.5mm
205/60/15 = 627mm
205/55/15 = 605.5mm

Therefore the wheel and tyre combinations allowable under VSB14 would include, but not be limited to, the following which fall within manufacturer overall diameter specifications +/- 15mm (to be within 8% speedometer accuracy):
205/45/16 = 591mm
205/50/16 = 611mm
215/50/16 = 621mm
205/40/17 = 596mm
215/40/17 = 604mm
205/45/17 = 616mm
215/45/17 = 625mm
205/40/18 = 621mm
215/40/18 = 629mm
215/35/18 = 608mm
215/30/19 = 611mm
215/35/19 = 633mm


this is what i got when i used the tyre size calculator, are they within the specifications?



195/60-14 205/60-15 Difference
Diameter inches (mm) 23.21 (589.6) 24.69 (627) 1.47 (37.4) 6.3%
Width inches (mm) 7.68 (195) 8.07 (205) 0.39 (10) 5.1%
Circum. inches (mm) 72.92 (1852.28) 77.55 (1969.78) 4.63 (117.5) 6.3%
Sidewall Height inches (mm) 4.61 (117) 4.84 (123) 0.24 (6) 5.1%
Revolutions per mile (km) 868.84 (539.87) 817.02 (507.67) -51.83 (-32.2) -6%


Speedometer Difference
Speedo Reading Actual Speed
20 mph (32.19 km/h) 21.27 mph (34.23 km/h)
25 mph (40.23 km/h) 26.59 mph (42.79 km/h)
30 mph (48.28 km/h) 31.9 mph (51.34 km/h)
35 mph (56.33 km/h) 37.22 mph (59.9 km/h)
40 mph (64.37 km/h) 42.54 mph (68.46 km/h)
45 mph (72.42 km/h) 47.85 mph (77.01 km/h)
50 mph (80.47 km/h) 53.17 mph (85.57 km/h)
55 mph (88.51 km/h) 58.49 mph (94.13 km/h)
60 mph (96.56 km/h) 63.81 mph (102.69 km/h)
65 mph (104.61 km/h) 69.12 mph (111.24 km/h)

 

[Dave_GSR1.8]

Not sure how it is in NSW but in Victoria I think you can only go +2 on the rim diameter. So this would rule out any rim over 16" down here. Might be worthwhile checking it in NSW.

Happy (and hope) to stand corrected!!

 

[mathew_colville]

im not sure what your saying Dave_GSR1.8? maybe its the way i worded it

the rims i just took off were 16x7.5, ive taken them off for the time being as the dirt road i drive on is pretty bad after the rain and my guards arent rolled and are wrecking my guards, i had some 15x6 205/60r15 wheels laying around and chucked them on, thought this would fix my problem but the tyres are rubbing on the guards aswell (im guessing gsr guards are causing this), so i looked into it and stock gsr rims are 14inch 195/60/r14 and on the tyre size calculator i should be running 205/50r15, but most threads i have read on here are saying that evos (im guessing evo 3) run 205/60/r15

so what i am getting at is if 205/60/r15 are legal to use ill roll my guards and all will be good, if not i wont bother rolling my guards and ill get tyres that are legal and fit

 

[mathew_colville]

ok so im doing more research:

this is what i have found on the evo 3:
Wheels & Tyres:
- OZ: Alloy racing wheels 4x114.3 195-15 Et 46
- Michelin: 205/60 R15

This is what nsw rta says:
The outside diameter of the wheel and tyre combination must be no more than 15mm over the largest diameter
wheel and tyre combination specified for the vehicle and not more than 15mm below the smallest diameter wheel
and tyre combination specified for the vehicle.

so the 205/60r15 are 37.4mm larger in diameter than Stock gsr wheels so this is illegal, but the evo 3 has them as a stock item? this is where im confused?
Diameter inches (mm) 23.21 (589.6) 24.69 (627) 1.47 (37.4) 6.3%

 

[khubner1]

Not sure how it is in NSW but in Victoria I think you can only go +2 on the rim diameter. So this would rule out any rim over 16" down here. Might be worthwhile checking it in NSW.

Happy (and hope) to stand corrected!!

please see the following
http://www.infrastructure.gov.au/roads/vehicle_regulation/bulletin/pdf/NCOP11_Section_LS_Tyres_Suspension_Steering_V2_1Jan_2011%20v3.pdf specifically page 19
before you try and rebut my comment. this is the NCOP it has now as far as i am aware been adopted by EVERY state in Australia i believe only 2 states have made amendments SA and QLD. (qld's amendments mostly relate specifically to testing procedures and are irrelevant for the purpose of this conversation)

now
the +2inch rule has bee circulating for some time and i can equivocally tell you it's bogus! if you want to fit big fat 22" rims you can provided you can find rubber bands small enough to keep the overall rolling diameter within the +15mm -26mm rule for class ma motor vehicles

as listed here (from the above source)
[SIZE=13.5pt]4.2.4 Overall Nominal Diameter[/SIZE]
[SIZE=13.5pt]The overall diameter of any tyre fitted to a passenger car or passenger car derivative must not[/SIZE]
[SIZE=13.5pt]be more than 15mm larger or 26mm smaller than that of any tyre designated by the vehicle[/SIZE]
[SIZE=13.5pt]manufacturer for that model.[/SIZE]
[SIZE=13.5pt]The overall diameter of any tyre fitted to:[/SIZE]
[SIZE=13.5pt]4WD passenger vehicles specifically designed for off-road use (typically MC ADR[/SIZE]
[SIZE=13.5pt]category).[/SIZE]
[SIZE=13.5pt]All wheel drive[/SIZE]
[SIZE=13.5pt](AWD) vehicles including those AWD vehicles that may be[/SIZE]
[SIZE=13.5pt]certified as MC ADR category, (also commonly known as[/SIZE]
[SIZE=13.5pt]soft roaders)[/SIZE]
[SIZE=13.5pt]are not[/SIZE]
[SIZE=13.5pt]included in this category;[/SIZE]
[SIZE=13.5pt]4WD goods vehicles and their 2WD equivalents if the chassis and running gear are[/SIZE]
[SIZE=13.5pt]essentially the same as the 4WD version (N ADR category); or[/SIZE]
[SIZE=13.5pt]any medium weight goods vehicle (NA2, NB ADR category).[/SIZE]
[SIZE=13.5pt]Must not be more than 50mm larger or 26mm smaller than that of any tyre designated by the[/SIZE]
[SIZE=13.5pt]vehicle manufacturer for that vehicle.[/SIZE]
[SIZE=13.5pt]Note[/SIZE]
[SIZE=13.5pt]: Increases in tyre diameter are subject to compliance with all other requirements[/SIZE]
[SIZE=13.5pt]specified under this clause (Clause 4.2[/SIZE]
[SIZE=13.5pt]Non-Standard Tyres and Rims)[/SIZE]
[SIZE=13.5pt]and may[/SIZE]
[SIZE=13.5pt]therefore be limited by other factors such as insufficient clearance.[/SIZE]
[SIZE=13.5pt]Speedometer accuracy must be maintained for the selected tyre and rim combination to within[/SIZE]
[SIZE=13.5pt]the degree of accuracy specified in ADR 18 where applicable. It is suggested that the degree of[/SIZE]
[SIZE=13.5pt]accuracy is in accordance with the most recent version of ADR18.[/SIZE]

 

[Dave_GSR1.8]

Sorry Mat, I stand corrected! Any of those wheel sizes you listed will work.

I decided to see what Vic Roads website says and what they say supports your original post (and Khubner's). I will have to speak to my mechanic as they mentioned something about the +2 rule the other day, looks like they need to brush up on the rules!!

 

[EVOCPE]

You'll be fine with that combo Mat, that's the same size I have on my Oz Racing wheels and passed full inspection and engineering

 

[mathew_colville]

You'll be fine with that combo Mat, that's the same size I have on my Oz Racing wheels and passed full inspection and engineering

have you ever tested your speed accuracy with that wheel combo? I dont want to be doing 100kms/hr on my speedo but im really doing 106kms/hr especially past a speed camera (thats going by the speedometer difference in the first post)

 

[mathew_colville]

so i tested the speed accuracy with the 205/60r15 and at 20kms/hr it was approx 4 kms out
tested it with the 16's and it was maybe 1km out, closer to spot on

i used a navigation system thing to check it so it might not be 100% accurate but in saying that the difference still might be enough to get you a ticket one day

 

[EVOCPE]

Yeh that was part of my engineering, he had to check the klms were correct with his GPS with them wheels

I'll send you a screen shot of my engineers cert and the size/klms etc

 

[EVO-00X]

Hey I wrote that list on the EVO tyre and wheel combos in the first post! That was part of my engineering process too back in 2008-2009.
Obviously the closer to the factory overall wheel/tyre diameter the closer the speedo will read, but remember, any change in overall diameter will throw the speedo out. There are millions of people out there driving with speedos out by a little bit.
There's nothing you can do about it unless you install a different number of tooth speedo gear and double check it against a GPS system. But even then one tooth difference could through it completely way off in speed reading.
I wouldn't worry about a speedo being out by 7%-8% at 110kmh. Its perfectly OK (engineer will pass up to8% accuracy) plus the fact that different car manufacturers and mech/electrical speedos will be out a little from eachother anyway. What is the benchmark? So many variables.
That's why the Police usually wont hassle you up to 7km more or 10% more than the posted speed limit - although they will never admit it in public!!

 

[khubner1]

adr's actualy state odo must read actualy speed to and accuracy of +10% it used to say +-10% meaning it could go either way i was going to fight a speeding fine on this very point until i found the document had been amended to remove the -10%

 

[Dave_GSR1.8]

In Victoria they are a bit tougher than 10%, they subtract 3 from the radar reading and if you are more than 3kmh over you get a fine, so 10% at 60kmh but less than 10% at 100kmh. If the adr's no longer say "-10%" then thay can do that. I suppose if you are reading +10% you would have to be well over the indicated speed limit to cop a fine so maybe not too bad. My speedo is optimistic even on OE wheels and tyres so I guess one would have to careful when playing around with different tyre and wheel combos.

As an aside do amended ADR's retrospectively apply to old cars ? Would the -10% still apply to a 1994 CC GSR (if that was what in place at that time) ?

 

[khubner1]

ok so here is adr 18/00 for 88-93
18.5. SPEEDOMETERS AND ODOMETERS (ALL VEHICLES)
18.5.1. Speedometers
18.5.1.1. Unless otherwise 'Approved', every vehicle shall be fitted with a speedometer which shall:
18.5.1.1.1. indicate vehicle speed only in kilometres per hour and
18.5.1.1.2. indicate the actual vehicle speed, for all speeds above 40 km/h, to an accuracy of ± 10 percent
18.5.1.2. The speedometer shall be installed so that its indication is readily visible to the driver when seated in the normal driving position.
18.5.2. Odometers
18.5.2.1. Every vehicle other than L-group vehicles shall be fitted with an odometer which shall:
18.5.2.1.1. indicate distance travelled in one kilometre units (or less) from 1 to 999,999 kilometres; and
18.5.2.1.2. indicate the actual distance travelled by the vehicle to an accuracy of ±4 per cent.
18.5.2.2. Every vehicle of category LC and LD shall be fitted with an odometer which shall:
18.5.2.2.1. indicate distance travelled in one kilometre units from I to 99,999 kilometres and
18.5.2.2.2. indicate the actual distance travelled by the vehicle to an accuracy of ± 4 percen

and here 18/01 for 93-95
18.5. SPEEDOMETERS AND ODOMETERS (ALL VEHICLES)
18.5.1. Speedometers
18.5.1.1. Unless otherwise ‘Approved’, every vehicle shall be fitted with a speedometer which shall:
18.5.1.1.1. indicate vehicle speed only in kilometres per hour; and
18.5.1.1.2. indicate the actual vehicle speed, for all speeds above 40 km/h, to an accuracy of + 10 per cent.
18.5.1.2. The speedometer shall be installed so that its indication is readily visible to the driver when seated in the normal driving position.
18.5.2. Odometers
18.5.2.1. Every vehicle other than LA; LB and LEM group vehicles shall be fitted with an odometer which shall:
18.5.2.1.1. indicate distance travelled in one kilometre units (or less) from 1 to 999,999 kilometres; and
18.5.2.1.2. indicate the actual distance travelled by the vehicle to an accuracy of + 4 per cent.
18.5.2.2. Every vehicle of category LC, LD and LEM shall be fitted with an odometer which shall:
18.5.2.2.1. indicate distance travelled in one kilometre units from 1 to 99,999 kilometres; and
18.5.2.2.2. indicate the actual distance travelled by the vehicle to an accuracy of + 4 per cent

i'll let you play spot the difference

 

[khubner1]

but then there's 18/02 which came in effect in 95 through 06
18.5. SPEEDOMETERS AND ODOMETERS (ALL VEHICLES)
18.5.1. Speedometers
18.5.1.1. Unless otherwise ‘Approved’, every vehicle must be fitted with a speedometer which must:
18.5.1.1.1. indicate vehicle speed only in kilometres per hour; and
18.5.1.1.2. indicate the actual vehicle speed, for all speeds above 40 km/h, to an accuracy of ± 10 per cent.
18.5.1.2. The speedometer must be installed so that its indication is readily visible to the driver when seated in the normal driving position.
18.5.2. Odometers
18.5.2.1. Every vehicle other than LA, LB and LEM group vehicles must be fitted with an odometer which must:
18.5.2.1.1. indicate distance travelled in one kilometre units (or less) at least from 1 to 600,000 kilometres (for MA, MB and MC category vehicles) and from 1 to 999,999 kilometres for all other category vehicles; and
18.5.2.1.2. indicate the actual distance travelled by the vehicle to an accuracy of ± 4 per cent.
18.5.2.2. Every vehicle of category LC, LD and LEM must be fitted with an odometer which must:
18.5.2.2.1. indicate distance travelled in one kilometre units from 1 to 99,999 kilometres; and
18.5.2.2.2. indicate the actual distance travelled by the vehicle to an accuracy of ± 4 per cent.

my car being a dec 94 build would fall into 18/01 (starts 01/01/93 ends 01/07/95). but i'm no lawyer or law enforcer and couldn't tell you which adr's exactly the car must comply to i assume you would go to the one that corresponds with the year of your manufacture. BUT it could also be the adr's that apply to the first of the generation granted adr compliance my car was complied feb of 95 and still falls under adr 18/01 but if it was complied in July the correct adr i would think would be 18/02. only way to really be sure would be to ask your local transport authority which adr's your car was complied to. they have a book that tells them all of this.

 

[Dave_GSR1.8]

Wow! Thanks Khubner.

By the looks of this I coudn't play the ADR card as I fall under the 18/01 iteration. Mind you even if I did and it worked it would be a pyrrhic victory. Sigh...

 

[mathew_colville]

thanks everyone for the info and yes evo-00x i did steal your evo tyre and wheel combo info thankyou for that

i took the 205/60r15s off as i couldnt even get down my driveway (not a normal driveway, 1km long dirt road with lots of bumps) without it hitting my guards, rubbing on the front plastic, rubbing on the side plastic when turning full lock and i think it may have even nicked the top of the strut tower from what i could see, i dont know how you guys use them :blink: