Author Topic: Spare wheel size question  (Read 11290 times)

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Offline HughBT

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Spare wheel size question
« on: June 04, 2016, 10:57:00 am »
Hi

I have got 18" alloys and no spare.

I am looking at doing the modifications discussed elsewhere on this forum  to fit a spare with my Bose sub-woofer but am not keen to shell out for another alloy rim if I can have a steel for hopefully rare use, but can only find 16" steel rims.

Can I drive on 3 18" and one 16"?  Sorry if it is a really stupid question!!

Offline Willpower

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Re: Spare wheel size question
« Reply #1 on: June 04, 2016, 01:11:09 pm »
You can provided that the wheel/tyre combination has the same rolling radius as your 18" wheels.  BUT ONLY AS A TEMPORARY SITUATION

Firstly you will need to find a steel wheel with the same nut fitments relating to number, positioning and offset. Then you will need to fit it with a tyre with a larger sidewall size (profile)  to accommodate the fact that you have a smaller wheel.   I'm sure that you will find that other members have done this and will give you more specific details in due course.
Look at life through the windscreen, not the rearview mirror.

Offline stevem100

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Re: Spare wheel size question
« Reply #2 on: June 04, 2016, 05:14:57 pm »
A skinny spare get you home wheel is 16 inch rim with a large side wall tyre bringing back to 19 inch and that's on my gen 3 sport nav i have seen posts that if you just want a skinny spare there on planet e-bay but you will be looking to match your total wheel size watch out for the difference in profile of the tyre. hope this helps  ;D
cheers steve  8)

Offline HughBT

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Re: Spare wheel size question
« Reply #3 on: June 04, 2016, 05:28:45 pm »
Thanks guys.

So to make up the 2" difference, i.e 50mm,  I need an extra 25mm on the profile to get the same total diameter?  I reckon that means I would need a 70mm profile on a 16" would go with a 45mm profile on an 18" wheel. I wonder how that would feel driving, even just on "Get me home" basis?

I'm thinking that for about £50 extra I probably should get a budget 18"alloy and a budget 225/45 tyre. Thoughts anyone?

Offline HughBT

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Re: Spare wheel size question
« Reply #4 on: June 04, 2016, 05:31:40 pm »
A skinny spare get you home wheel is 16 inch rim with a large side wall tyre bringing back to 19 inch and that's on my gen 3 sport nav i have seen posts that if you just want a skinny spare there on planet e-bay but you will be looking to match your total wheel size watch out for the difference in profile of the tyre. hope this helps  ;D
cheers steve  8)

The problem with a skinny is it cant go on the front I'm told, so if I get a front puncture late at night in the rain I've got to take one off the rear to put the skinny on then put the one from the rear on the front before I can go any further.  Nightmare!!

Offline Willpower

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Re: Spare wheel size question
« Reply #5 on: June 04, 2016, 06:57:40 pm »
The problem with a skinny is it cant go on the front I'm told, so if I get a front puncture late at night in the rain I've got to take one off the rear to put the skinny on then put the one from the rear on the front before I can go any further.  Nightmare!!

You are quite correct. So you have to weigh up the options.

a) A skinny =  Can't use on the front, maximum speed no greater than 50mph and must be changed ASAP
b) A Steel 16" + appropriate sized tyre = Heavier, must match fitment and offset. Can be used on the rear
c) An alloy + appropriate tyre = Lighter, must match fitment and offset. Can be used on the rear
d) Run flat tyres = Expensive
 
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Offline HughBT

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Re: Spare wheel size question
« Reply #6 on: June 05, 2016, 07:17:41 am »
Hadn't considered the weight issue, I think I'll go with the alloy option.

Thanks for your input. :)

Offline stevem100

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Re: Spare wheel size question
« Reply #7 on: June 05, 2016, 01:10:05 pm »
But i don't think that will fit in the wheel well only in the boot ? :( If that's OK go ahead. 8)

Offline HughBT

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Re: Spare wheel size question
« Reply #8 on: June 05, 2016, 07:40:07 pm »
Thanks, I am advised that the GenerationII well is big enough for a full size but intend to check it out before I start buying anything or slicing up the foam filler piece. 8)

Offline slavikost

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Re: Spare wheel size question
« Reply #9 on: September 10, 2016, 02:54:27 pm »
Full size wheel is the best option.And cheapest also.I have purchased two allow wheels for 100 pounds from e-bay(seller didn`t want to sell just one) .Installed my old tyres.Kept one for myself and sold the other+tyre for 80 pounds on ebay again.So it cost me 20 pounds+20 fitting to have in the boot  exactly the same wheel like the rest 4 on the car.And just two weeks after that in the middle of nowhere hitting the hidden kerb  gave me hole in the side of the tyre in which I could easily insert my finger.If I had still the dodgy foam in the boot I can spend there few days until I menage to repair the tyre.Of course breakdown cover is easy option but in this case if you don`t have additional tyre cover the tyre is useless and cant be fix at the moment even from tyre fix van.