What is a space saver spare wheel?

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A space saver spare wheel is an emergency spare wheel and tyre, only to be use in an emergency until you get your failed tyre fixed.

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Why don’t we get a full-size wheel and tyre anymore?

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Due to the European emission laws vehicle manufactures must improve engine emissions year on year, the cheapest way of doing this is to make the vehicle lighter, less weight = better emissions! unfortunately, this means for many car buyers we have to say good bye to your spare wheel as we know it, some will get a full-size spare wheel and tyre great and some will get a space saver wheel and tyre also great. Now over the last couple of years we “Tyremen” have seen a massive increase in calls asking for a spare wheel because lots of manufactures have opted out of offering a spare full stop. This is not a good move for car newer car buyers as manufactures have replaced this with a compressor and a tub of glue which to be honest is useless.   

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Are space saver wheels safe?

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Yes of course they are, if used correctly and driven no faster then 50-mph they should be no issues, on some vehicles it may feel a little different especially on the front due to the wheel been narrow this could be felt through the steering, drive with care and it will get you home safely.

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What’s the solution / were can I buy a space saver spare wheel and tyre kit?

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You can go to the main dealer and buy one, but I have heard really high prices been quoted, for example Mercedes E-Class 2018 wanted £450.00 for there kit. We have spent many years looking to offer our customers the option to buy a space saver kit, yes these are aftermarket meaning not OE but these are 100% safe and are as usable as the OE option from main dealer but at a lesser cost.

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How long will it last?

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The spare tyre will last a good while, however please remember this is just a temporary fix and only to be used for a short period of time and not to be left on for 6 months or 6000 miles later as this is not what there are designed for!

 

Why is my space saver spare wheel smaller in diameter - should this not be the same?

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We have lots of past customers which have changed wheels and tyres smaller or bigger, and we have advised you must keep the rolling radius the same or within 2.5 - 3%, this is a must when changing to bigger or smaller wheels across all four to avoid a misreading speedometer and upsetting the gear ratio. A space saver can be up to 4-5% smaller shock!! Please remember these are only to be used as an emergency and will not be on long enough to cause an issue. Having said this the majority are within the 2.5% allowance.

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But how does this work & how can a wheel that looks so different in size still work on my car?

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There is a couple of different diameters or rolling circumference’s when it comes to PCR tyres “Passenger car tyres” let pick on the most popular sizes starting with 225/45r17 this has a diameter of 24.97”.

 

To keep your cars speedometer and gear ratio as it should be we need to get as close as possible to this with our space saver tyre. In this case we need a tyre which is as close to 24.97” as possible, luckily we have the 125/80R17 space saver tyre which measures 24.87”.

 

To work this out yourself as I know our customer love to learn these things, please follow this simple math:

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Tyre size 225/45R17.

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First, you would multiply section width by profile

 

Section width (225) x profile (45) = 10’125

 

Secondly, divide (10’125) by 2540 and multiply by 2 = 7’972

 

Thirdly, add the rim diameter (17”) 7’972 + 17 = 24.97”

 

Full sum below:

 

OE tyre size = 225/45R17

 

1, 225x45/2540x2+17 = 24.97 (“)

 

Space saver tyre size = 145/70R17

 

1, 125X80/2540X2+17 = 24.87 (“)

 

As you can see the two tyres are almost a match in diameter in fact 0.10” difference of 0.04%, really this is all you need to be concerned about when we have 2.5-% to play with. Yes, the tyre is 4” narrower, used properly these will save the day.

 

Thanks for reading Chris sanders