225/40/18" Wheels Versus Standard 205/55/16"

ckosm · 01-08-2003, 08:26

Hi guys,

I would appreciate your views/opinions on changing my original 205/55/16" wheels with the larger 225/40/18" (BBS-RC alloys). The reason i would like to proceed this way is that I get alot of wheel-spin with 1st, 2nd, and on changing to 3rd gear when reving above 3-3.500 rpms. I just undermine that the car was measured last year and produced 210hp/300Nm with a broken DV realized some days later and currently has some newer mods like a free-flow cat-back exhaust and must have therefore some more power, as it is felt like this.
Will the 225/40/18" wheels slow the car down and will they reduce wheel-spin to a more acceptable level? Is it worth the money, or losses will be greater than gains? Should I compromise in between and go for the 225/45/17" wheels?

Any input will be welcome by all of you in this forum

Thanks

***ncarring*** · 01-08-2003, 09:48

I would think you would actually get more wheelspin with the lower profile tyres since the rolling radius (I assume you have calculated it this way) is not changing, therefore neither is the torque at the wheels causing the wheelspin. The standard tyres will absorb more of the torque before losing their grip. JMHO.

SkodiRS · 01-08-2003, 11:05

Chris,

should you be going to 225/45/18 as opposed to a 225/40/18 to keep the rolling radius the same? That said the difference may be too small to make a difference on the speedo.

With the wider tyre you would get better grip generally but I don't know about standing starts. Assuming the rolling radius are the same, the torque will be the same at the wheels. There will be more surface contact area due to the wider tyres so I would assume that there would be more grip.......perhaps?

I'm sure those in the know will steer you right.

Cheers.
Adrian.

devonutopia · 01-08-2003, 11:31

18s would look the daddy in my opinion, compared to 16s. I imagine it would corner better too as the tyres will be wider, and there would be less sidewall flex in 35s compared to 55s.

Don't go by my opinion though, as I'm no expert. What I do know is my current setup (205/40*17) is much better than the standard 185/60*14 the car came with.

Monkey Boy · 01-08-2003, 13:08

Grip should be increased due to the wider tyre having a bigger foot print.

I am looking at 20" wheels for my vRS but designs are limited so may go for 19's. (My friend owns a alloy wheel and car accessory shop so can get some wheels at cost)

Eric_R · 01-08-2003, 13:09

The change from 16 to 17 or 18" does not improve the grip.
What is important is to choose a more high performance tyre
that is stickier and has softer compound.
If you choose cheap heavy wheels and tyres acceleration and
comfort will suffer but the "racing image" will be better.

***ncarring*** · 01-08-2003, 13:14

I'll second that, Eric. I admit I ignored the extra width in my first response. Still trying desperately to wear out my cheap slippy tyres so I can get some grippier ones - only another 10k miles or so to go

(Of course the paradox is that being cheap and hard, and therefore slippy, they last longer and can't be got rid of so quickly

)

**robmawer** · 01-08-2003, 13:16

You're not trying hard enough Nick...

Rob.

***ncarring*** · 01-08-2003, 13:18

Trying too hard + slippy tyres = hedge

ckosm · 01-08-2003, 17:37

Quote:

Originally posted by SkodiRS in this post
Chris,

should you be going to 225/45/18 as opposed to a 225/40/18 to keep the rolling radius the same? That said the difference may be too small to make a difference on the speedo.

With the wider tyre you would get better grip generally but I don't know about standing starts. Assuming the rolling radius are the same, the torque will be the same at the wheels. There will be more surface contact area due to the wider tyres so I would assume that there would be more grip.......perhaps?

I'm sure those in the know will steer you right.

Cheers.
Adrian.

Thanks Adrian...!!!

The rolling diameter of the wheels are as follows (according to my calculations):
205/55/R16 = 631.9 mm
225/45/R17 = 634.3 mm
225/40/R18 = 637.2 mm

So the difference in rolling diameter between 225/40/R18 and 205/55/R16 is 5.3mm (rolling radius difference 5.3/2=2.65mm), while the difference between 225/45/R17 and 205/55/R16 is 2.4mm (rolling radius difference 2.4/2=1.2 mm). I think that rolling radius differences are negligible in both cases, as you say.

skodaw · 01-08-2003, 20:36

Switching to 225/40/18 tyres should give better grip for 2 reasons.

1.Wider tyre footprint = wider area to disperse torque.
2.tyres in this size tend to be "Sport" orientated and will usually have softer"Grippier" compound,

Guess I will find out soon myself -- collected my Kahn RS-S 18's today - will also be using 225/40/18 rubber....time will tell

SkodiRS · 01-08-2003, 22:56

Dave,

post pics of your new wheels when you get a chance.

Cheers.
Adrian.

***ncarring*** · 01-08-2003, 23:00

Quote:

Originally posted by skodaw in this post
Switching to 225/40/18 tyres should give better grip for 2 reasons.

1.Wider tyre footprint = wider area to disperse torque.
2.tyres in this size tend to be "Sport" orientated and will usually have softer"Grippier" compound,

Guess I will find out soon myself -- collected my Kahn RS-S 18's today - will also be using 225/40/18 rubber....time will tell

I am running on 225/45ZR17 tyres and they are the crappiest, hardest, slippiest pile of

I've ever had the pleasure .... Grippy, pah!!

Dutch4x4 · 01-08-2003, 23:04

Name and shame, please, Nick...

***ncarring*** · 01-08-2003, 23:07

You would never have heard of them:

Fronts: "Star Performers"
Rears: "Roadhogs"

Equally

... but tight@rsed old me is waiting til they are worn out before getting better rubber - it's my business as well as my pleasure, after all ...

Dutch4x4 · 01-08-2003, 23:42

Let the pleasure win over business this time, and get yourself TWO super-grippy new tyres.

Mount them on the front, and dump the old ones in the boot.

Get the car to a (Briskoda-organized?) airfield track day and smoke those b*ggers at the rear!

If the tyres are really that bad and gripless (and with another two heavy piles of crap in the back), this set-up should equal mega-drifts and instant RWD-style fun. Rears gone? Mount the pair in the boot and carry on where you left off but leave enough profile for a careful drive home.

Then buy another pair of grippy tyres and put them on the rear for continued safe but more enjoyable motoring.

(Ah, but you aren't the car-hooligan type, are you?

)

skodaw · 02-08-2003, 08:08

When I said most tyres of that size were of a sportier nature -- I didn't think anyone would be so tight as to use recycled rubber bands as tyres.........

***ncarring*** · 02-08-2003, 09:20

Quote:

Originally posted by Dutch4x4 in this post
(Ah, but you aren't the car-hooligan type, are you? )

I guess not

- have never taken my car on track - don't want to write it off with no insurance. I need it to get to work and back.

***ncarring*** · 02-08-2003, 09:22

Quote:

Originally posted by skodaw in this post
When I said most tyres of that size were of a sportier nature -- I didn't think anyone would be so tight as to use recycled rubber bands as tyres.........

Just running the tyres that were on the car when I bought it. When I looked it over the two rears were just about dead. Then when I picked it up, lo and behold the dealer had fitted two new ones (the "Star Performers"). Kinda goes against the grain to throw them away when brand new. Now 20k miles later they're two thirds worn ....

skodaw · 02-08-2003, 09:34

I know what you mean,having just had to fork out for 4 18" tyres.Although I think I got a cracking deal from the company my dealer uses - 4 225/40/18z Conti Sport Contact 2 for £125 each.

Had I not been able to get such a deal, I probably would have waited,as the original tyres still have 5mm of tread....

ckosm · 03-08-2003, 09:28

Thanks for all your answers guys...

Your input is much appreciated...

The other issue I'd like to bring into discussion is whether the 225/40/18" wheels will slow the car down off the line compared to 225/45/17" or 205/55/16" wheels.

P.S. I'm planning to put 225/40/18" wheels with BBS-RC alloys (very light and resistant) with Michelin Pilot Sport or Goodyear Eagle F1-G3 tyres...

01-08-2003, 08:26	#1
ckosm Briskodian Join Date: Jan 2003 Location: Athens, Greece Posts: 38 Members Car: Thanks: 0 Thanked 0 Times in 0 Posts	225/40/18" Wheels Versus Standard 205/55/16" Hi guys, I would appreciate your views/opinions on changing my original 205/55/16" wheels with the larger 225/40/18" (BBS-RC alloys). The reason i would like to proceed this way is that I get alot of wheel-spin with 1st, 2nd, and on changing to 3rd gear when reving above 3-3.500 rpms. I just undermine that the car was measured last year and produced 210hp/300Nm with a broken DV realized some days later and currently has some newer mods like a free-flow cat-back exhaust and must have therefore some more power, as it is felt like this. Will the 225/40/18" wheels slow the car down and will they reduce wheel-spin to a more acceptable level? Is it worth the money, or losses will be greater than gains? Should I compromise in between and go for the 225/45/17" wheels? Any input will be welcome by all of you in this forum Thanks __________________ Chris Octavia 1.8T-ÌÔÌ 240hp (K04 conversion), RS6-DV, Koni-Eibach 3.5cm, Powerflex bushes, RS brakes, wheels BBS-RC 8x18"/Michelin Pilot Sport-2 (225/40/R18)

01-08-2003, 09:48	#2
*ncarring* Don't talk, drive! Join Date: Feb 2003 Location: The B roads of Britain Posts: 12,953 Members Car: 1983 Porsche 928S / 1972 MGB GT Thanks: 16 Thanked 94 Times in 77 Posts	I would think you would actually get more wheelspin with the lower profile tyres since the rolling radius (I assume you have calculated it this way) is not changing, therefore neither is the torque at the wheels causing the wheelspin. The standard tyres will absorb more of the torque before losing their grip. JMHO. __________________ Nick North Wiltshire RoADAR

01-08-2003, 11:05	#3
SkodiRS BRISKODA Staff Join Date: Oct 2002 Location: darkest Hampshire Posts: 8,650 Members Car: Thanks: 0 Thanked 17 Times in 13 Posts	Chris, should you be going to 225/45/18 as opposed to a 225/40/18 to keep the rolling radius the same? That said the difference may be too small to make a difference on the speedo. With the wider tyre you would get better grip generally but I don't know about standing starts. Assuming the rolling radius are the same, the torque will be the same at the wheels. There will be more surface contact area due to the wider tyres so I would assume that there would be more grip.......perhaps? I'm sure those in the know will steer you right. Cheers. Adrian. __________________ Adrian.

01-08-2003, 11:31	#4
devonutopia Mongreller Join Date: Apr 2003 Location: Exeter / Devon Posts: 30,081 Members Car: Skoda Fabia Mongrel Images: 5 Thanks: 75 Thanked 352 Times in 295 Posts	18s would look the daddy in my opinion, compared to 16s. I imagine it would corner better too as the tyres will be wider, and there would be less sidewall flex in 35s compared to 55s. Don't go by my opinion though, as I'm no expert. What I do know is my current setup (205/4017) is much better than the standard 185/6014 the car came with. __________________ Jason - Only a Skoda. Custom Fabia Bonnet Lifter Kits - £45! Click Me. Cheesy bonnet lifter video to "raise me up" http://www.youtube.com/watch?v=hMnGECEi5Oc See the mongrel's 260bhp Dyno Video!

01-08-2003, 13:08	#5
Monkey Boy Briskodian Join Date: Jul 2003 Location: Under The Bonnet Posts: 645 Members Car: Fabia VRS Thanks: 0 Thanked 9 Times in 9 Posts	Grip should be increased due to the wider tyre having a bigger foot print. I am looking at 20" wheels for my vRS but designs are limited so may go for 19's. (My friend owns a alloy wheel and car accessory shop so can get some wheels at cost) __________________ Octavia VRs mk1

01-08-2003, 13:09	#6
Eric_R Briskodian Join Date: Nov 2002 Location: Stockholm Posts: 41 Members Car: Thanks: 0 Thanked 0 Times in 0 Posts	The change from 16 to 17 or 18" does not improve the grip. What is important is to choose a more high performance tyre that is stickier and has softer compound. If you choose cheap heavy wheels and tyres acceleration and comfort will suffer but the "racing image" will be better.

01-08-2003, 13:14	#7
*ncarring* Don't talk, drive! Join Date: Feb 2003 Location: The B roads of Britain Posts: 12,953 Members Car: 1983 Porsche 928S / 1972 MGB GT Thanks: 16 Thanked 94 Times in 77 Posts	I'll second that, Eric. I admit I ignored the extra width in my first response. Still trying desperately to wear out my cheap slippy tyres so I can get some grippier ones - only another 10k miles or so to go (Of course the paradox is that being cheap and hard, and therefore slippy, they last longer and can't be got rid of so quickly ) __________________ Nick North Wiltshire RoADAR

01-08-2003, 13:16	#8
robmawer Briskodian Join Date: Jan 2003 Location: Rochdale Posts: 12,476 Members Car: Octavia 1.6 Ambiente Thanks: 2 Thanked 74 Times in 67 Posts	You're not trying hard enough Nick... Rob. __________________

01-08-2003, 13:18	#9
*ncarring* Don't talk, drive! Join Date: Feb 2003 Location: The B roads of Britain Posts: 12,953 Members Car: 1983 Porsche 928S / 1972 MGB GT Thanks: 16 Thanked 94 Times in 77 Posts	Trying too hard + slippy tyres = hedge __________________ Nick North Wiltshire RoADAR

01-08-2003, 20:36	#11
skodaw Briskodian Join Date: Jun 2003 Location: This area is under construction - please call back later :) Posts: 3,186 Members Car: Skoda Fabia vRS Thanks: 2 Thanked 9 Times in 5 Posts	Switching to 225/40/18 tyres should give better grip for 2 reasons. 1.Wider tyre footprint = wider area to disperse torque. 2.tyres in this size tend to be "Sport" orientated and will usually have softer"Grippier" compound, Guess I will find out soon myself -- collected my Kahn RS-S 18's today - will also be using 225/40/18 rubber....time will tell __________________ Dave '05 Silver Fabia vRS

01-08-2003, 22:56	#12
SkodiRS BRISKODA Staff Join Date: Oct 2002 Location: darkest Hampshire Posts: 8,650 Members Car: Thanks: 0 Thanked 17 Times in 13 Posts	Dave, post pics of your new wheels when you get a chance. Cheers. Adrian. __________________ Adrian.

01-08-2003, 23:04	#14
Dutch4x4 Briskodian Join Date: Feb 2003 Location: kicking up feet in the Formula Stealth paddock Posts: 3,153 Members Car: 1.8T Elegance Hatchback 4x4 Thanks: 0 Thanked 0 Times in 0 Posts	Name and shame, please, Nick... __________________ Mrs D's Briskoda: Octavia 4x4 turbo (2003), Oettinger 210, Koni Sport, MAD Sportive, Dotz Le Mans 17", Bridgestone Potenza S-03, sports interior. And a Fiesta ST (2006) for myself...

01-08-2003, 23:07	#15
*ncarring* Don't talk, drive! Join Date: Feb 2003 Location: The B roads of Britain Posts: 12,953 Members Car: 1983 Porsche 928S / 1972 MGB GT Thanks: 16 Thanked 94 Times in 77 Posts	You would never have heard of them: Fronts: "Star Performers" Rears: "Roadhogs" Equally ... but tight@rsed old me is waiting til they are worn out before getting better rubber - it's my business as well as my pleasure, after all ... __________________ Nick North Wiltshire RoADAR

01-08-2003, 23:42	#16
Dutch4x4 Briskodian Join Date: Feb 2003 Location: kicking up feet in the Formula Stealth paddock Posts: 3,153 Members Car: 1.8T Elegance Hatchback 4x4 Thanks: 0 Thanked 0 Times in 0 Posts	Let the pleasure win over business this time, and get yourself TWO super-grippy new tyres. Mount them on the front, and dump the old ones in the boot. Get the car to a (Briskoda-organized?) airfield track day and smoke those b*ggers at the rear! If the tyres are really that bad and gripless (and with another two heavy piles of crap in the back), this set-up should equal mega-drifts and instant RWD-style fun. Rears gone? Mount the pair in the boot and carry on where you left off but leave enough profile for a careful drive home. Then buy another pair of grippy tyres and put them on the rear for continued safe but more enjoyable motoring. (Ah, but you aren't the car-hooligan type, are you? ) __________________ Mrs D's Briskoda: Octavia 4x4 turbo (2003), Oettinger 210, Koni Sport, MAD Sportive, Dotz Le Mans 17", Bridgestone Potenza S-03, sports interior. And a Fiesta ST (2006) for myself...

02-08-2003, 08:08	#17
skodaw Briskodian Join Date: Jun 2003 Location: This area is under construction - please call back later :) Posts: 3,186 Members Car: Skoda Fabia vRS Thanks: 2 Thanked 9 Times in 5 Posts	When I said most tyres of that size were of a sportier nature -- I didn't think anyone would be so tight as to use recycled rubber bands as tyres......... __________________ Dave '05 Silver Fabia vRS

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02-08-2003, 09:34	#20
skodaw Briskodian Join Date: Jun 2003 Location: This area is under construction - please call back later :) Posts: 3,186 Members Car: Skoda Fabia vRS Thanks: 2 Thanked 9 Times in 5 Posts	I know what you mean,having just had to fork out for 4 18" tyres.Although I think I got a cracking deal from the company my dealer uses - 4 225/40/18z Conti Sport Contact 2 for £125 each. Had I not been able to get such a deal, I probably would have waited,as the original tyres still have 5mm of tread.... __________________ Dave '05 Silver Fabia vRS

03-08-2003, 09:28	#21
ckosm Briskodian Join Date: Jan 2003 Location: Athens, Greece Posts: 38 Members Car: Thanks: 0 Thanked 0 Times in 0 Posts	Thanks for all your answers guys... Your input is much appreciated... The other issue I'd like to bring into discussion is whether the 225/40/18" wheels will slow the car down off the line compared to 225/45/17" or 205/55/16" wheels. P.S. I'm planning to put 225/40/18" wheels with BBS-RC alloys (very light and resistant) with Michelin Pilot Sport or Goodyear Eagle F1-G3 tyres... __________________ Chris Octavia 1.8T-ÌÔÌ 240hp (K04 conversion), RS6-DV, Koni-Eibach 3.5cm, Powerflex bushes, RS brakes, wheels BBS-RC 8x18"/Michelin Pilot Sport-2 (225/40/R18)

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225/40/18" Wheels Versus Standard 205/55/16"

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