Hi Guys,hopefully my new Scout will be with me soon.

I was going to get a spare set of wheels and tyres.The dealer is recommending the standard 15 inch octavia steel wheels and Vredestein snowtrac 195/65 x15 tyres.

The scout has 180 mm ground clearance on its standard 225/50 x17 combo. Does anyone know please if my ground clearance or rolling circumference and speedo reading will be adversely affected.Presumably the recommendation is so as not to negate the new Skoda warranty Any info would be much appreciated. Thank you. Never had a Skoda before so looking forward to this one.Octy Scout 2.0Tdi in Cappuchino Metallic.

Hi Guys,hopefully my new Scout will be with me soon.

I was going to get a spare set of wheels and tyres.The dealer is recommending the standard 15 inch octavia steel wheels and Vredestein snowtrac 195/65 x15 tyres.

The scout has 180 mm ground clearance on its standard 225/50 x17 combo. Does anyone know please if my ground clearance or rolling circumference and speedo reading will be adversely affected.Presumably the recommendation is so as not to negate the new Skoda warranty Any info would be much appreciated. Thank you. Never had a Skoda before so looking forward to this one.Octy Scout 2.0Tdi in Cappuchino Metallic.

As long as the outer radius is the same there will be no difference but It sounds like you have worked that out. The stock 4x4 runs 205/60/15 according to the brochure, the running gear Im sure is the same as the scout so "theoretically" these would be closest but yopu may not be able to get the 60 in winter rubber, hence the dealer saying 65.

There arec loads of size calculators on the net like this one, many probably better

http://www.tiresizecalculator.info/

First off, all of "ground clearance or rolling circumference and speedo reading" are effectively the same thing, if you're just changing wheels and tyres. The ground clearance is controlled by the rolling radius of the wheel and tyre combo, and there is a direct relationship between rolling radius, (2*pi*RR = RC) and circumference and hence speedo reading.

So we just need to calculate rolling radius of both wheel/tyre combos to see if there will be any significant effect. The general case is that tread width * aspect ratio + wheel size in mm gives rolling radius. So for the 225/50R17 we get (225*50/100) + (17*25.4/2) which is 112.5 + 215.9 for an RR of 328.4mm. The 195/65R15 gives (195*65/100) + 15*25.4/2) for 126.75+190.5 = 317.25.

Now we divide the new RR by the old one to see the effect on gearing - 317.25/328,4 = 0.966, or gearing is about 3.4% shorter, and old RR - new RR for ride height shows 11.15 mm lower.

Edited 26 February, 201016 yr by KenONeill

First off, all of "ground clearance or rolling circumference and speedo reading" are effectively the same thing, if you're just changing wheels and tyres. The ground clearance is controlled by the rolling radius of the wheel and tyre combo, and there is a direct relationship between rolling radius, (2*pi*RR = RC) and circumference and hence speedo reading.

So we just need to calculate rolling radius of both wheel/tyre combos to see if there will be any significant effect. The general case is that tread width * aspect ratio + wheel size in mm gives rolling radius. So for the 225/50R17 we get (225*50/100) + (17*25.4/2) which is 112.5 + 215.9 for an RR of 328.4mm. The 195/65R15 gives (195*65/100) + 15*25.4/2) for 126.75+190.5 = 317.25.

Now we divide the new RR by the old one to see the effect on gearing - 317.25/328,4 = 0.966, or gearing is about 3.4% shorter, and old RR - new RR for ride height shows 11.15 mm lower.

Thanks to Ken And Stuart.

thats useful info .It sounds like the smaller wheel set will not cause to much of a problem.With ride height due to snow we are having at the moment every bit helps but 11 mm isn't going to make the world of difference and it seems like snowtrac tyres have a good reputation on here. Cheers for now.

Not sure that they are correct in quoting 15" wheels as an alternative :wonder: The manual and the inside of the filler cap on my 08 Scout both quote 205/55/16 as the other standard option. Should be the same for the F/L Scout I would have thought. I doubt if the 15" will fit over the brakes.

I have 16" fitted with 205/55/16 Vredestein Snowtrac 3's and they are fantastic (see post here.) It will give you a slightly different rolling radius, which will cause a slight over read on the speedo 3%

I agree, 16" wheels with 205/55/16 tyres are the way to go. That is also the same size as the spare wheel in the Scout which could be useful.

Not sure that they are correct in quoting 15" wheels as an alternative :wonder: The manual and the inside of the filler cap on my 08 Scout both quote 205/55/16 as the other standard option. Should be the same for the F/L Scout I would have thought. I doubt if the 15" will fit over the brakes.

I have 16" fitted with 205/55/16 Vredestein Snowtrac 3's and they are fantastic (see post here.) It will give you a slightly different rolling radius, which will cause a slight over read on the speedo 3%

Can I ask where you got the Skoda badges from to cover up the Seat one on the wheel covers. I have got SEAT wheels as well.

try this tyre size site - it tells you the effect on speedo readings :

http://www.kouki.co.uk/utilities/visual-tyre-size-calculator

Can I ask where you got the Skoda badges from to cover up the Seat one on the wheel covers. I have got SEAT wheels as well.

I got them on ebay, there are usually quite a few around.

Hi Guys , thanks all for the info.I will get the dealer to re check his data.

Jules 59 thanks for the note re kouki website.I had a recce .It's brilliant, really helpful

Hi Guys , thanks all for the info.I will get the dealer to re check his data.

Jules 59 thanks for the note re kouki website.I had a recce .It's brilliant, really helpful

If you are getting technical info from a certain franchised dealer in Inverness; I have learned to check it for accuracy very carefully. http://briskoda.net/forums/public/style_emoticons/default/emoticon-0101-sadsmile.gif

Oh, I think Vredestein do Wintrac Extreme in the Scout tyre size but they are probably a bit pricier than snowtrac.

Edited 28 February, 201016 yr by Forester