full size spare

[PeterL]

As the wheel gets bigger the tyre profile gets smaller? But having said that perhaps as the margins are not really that much it might well explain why the Tekna looks so good? We're talking about less than an inch here!PeterL2014-05-10 19:03:38

[andrewjoseph]

http://tires.about.com/od/understanding ... zing.htmla quick google found the site above.

[DaveBerlin]

andrewjoseph, I am not making up this information when you ordered your QQ I would think that you had received Brochures and the Price List which includes the Technical Data of all models and this is where I got my information from. OK as mentioned by PeterL the Overall Heights are stated as being the same oddly enough 1.590mm + 5mm for the 4+4

Here is a quote (AA Based) :
You must always make sure that tyres on the same axle are of the same size and aspect ratio - your car will fail the MOT test if they're not - but the law makes an exception for temporary use spare wheels fitted in an emergency.
Temporary use spare wheels - non-standard spare/skinny spare - are increasingly being supplied as standard by car manufacturers to save space and weight. Generally these will be narrower than the standard size car tyres.

OK I am no Maths Teacher but this is how I calculated the Data :
16" Wheel with 215/65/R16 = 16 + 2.56 x 2 = 21,12" Dia (65mm Section = 2.56")
17" Wheel with 215/60/R17 = 17 + 2.36 x 2 = 21.72" Dia (60mm Section = 2.36")
19" Wheel with 225/45/R19 = 19 + 1.77 x 2 = 22.54" Dia (45mm Section = 1.77")
16" Wheel with 145/90/16 = 16 + 3.54 x 2 = 23.08" Dia (90mm Section = 3.54") Space Saver Wheel

So theoritically we are talking of the worst case scenario with a 16" Space Saver replacing a 16" Std. Wheel of being 23.08 - 21.12 = 1.96 / 2 = 0.98" and that therefore to me means the theoritical Axle position is 0.98" Higher.

If you take a look at "Non Tech QQ Discussions" there is another Subject called "Spare Tyre/ Gunk/ Jack etc" and there is some interesting comments there also.
I hope this now clears up this point and has not bored you - Over & Out - Regards Dave

[PeterL]

As I implied earlier there is a difference, less than an inch, and for both looks and indeed performance benefits.

[DaveBerlin]

andrewjoseph / PeterL, Thanks to you both but your comments they are good and the calculation one mentions Aspect Ratios which is different to what I calculated I used the tire depth. I think I will sleep on it tonite and look again tomorrow, but the Nissan info' is correct - Thanks Dave

[PeterL]

Sleep well David! Tolerance is much of my working life it seems, ranging from Colour Management and expectations through to customer expectations - I'll leave you to guess the easier one of the two!
PeterL2014-05-10 20:05:34

[DaveBerlin]

PeterL / andrewjoseph, I could not sleep had to re-calculate using the Aspect Ratios so this should be it :

16" 215/65 : 215 x 0.65 = 139.75 / 25.4 = 5.50 x 2 = 11.00 + 16 = 27"
17" 215/60 : 215 x 0.60 = 129 / 25.4 = 5.078 x 2 = 10.156 + 17 = 27.156"
19" 225/45 : 225 x 0.45 = 101.25 / 25.4 = 3.986 x 2 = 7.972 + 19 = 26.97"

16" 145/90 : 145 x 0.90 = 130.5 / 25.4 = 5.137 x 2 = 10.27 + 16 = 26.27" Space Saver

So what have we got finally is a difference of a max 27.156 - 26.27 = 0.886 / 2 = 0.443" (floor to Axle CL)
Well that was an exercise and what did it prove in the end virtually no difference - Thanks for your Time Dave ?Y??

[andrewjoseph]

tried to post this earlier.not boring me Dave, I just couldn't see the figures you came up with in Nissan data.Did you read the website I linked to?That explains it better than I can.And the 4 x4 is a slightly different beast with higher ground clearance.Yes, a temporary spare is exempt, but you were talking about 4 winter wheels/tyres that the salesman said had smaller diameter.
andrewjoseph2014-05-10 21:23:05

[DaveBerlin]

Andrewjoseph, what I posted above your last comment is the final calcs from your website info' (thanks for that cleared up things). The difference is under 1/2" and the Space Saver was what was classed as smaller 16". What we have to remember is this Aspect Ratio which proves whatever size wheel tire combination is used there is hardly any difference. It was a good exercise and some info' learned - Thanks Again Dave

[korky]

Guys - this is all intriguing stuff and an interesting read!

I think in conclusion what we are saying is that the 16" space saver is ok but only as a short term emergency use.

The 19s on the Tekna scare me as the profile is very low and it looks like the alloy edge is exposed and prone to kerbing