I've put 15 inch alloy wheels on my car, but the spare is a steel 14 inch - any risk of damage using spare ?

Question

I'm wondering if I ever needed to use the spare... cause its smaller.. if I'd be straining the axle ? If so I will look to get myself a fifth 15inch spare.

Thanks.

Answer 1

Provided you put lower profile tyres on your 15" wheels to maintain the same rolling radius as standard you will be OK.

If you didn't ensure that the tyre profile on the 15" wheels maintains the same profile as before, then you will have altered your cars gearing (which will affect performance and fuel consumption) and you will need to get your speedometer re-calibrated to suit the new tyres' rolling radius.

If you can provide the tyre sizes on both your 15" alloys and 14" spare (width, aspect ratio and rim diameter, e.g. 185/60R14) I can calculate if there has been a significant change in rolling radius.

It is still possible to drive with one tyre having a smaller rolling radius, but you will have to restrict the distance you travel and the speed you travel at, as well as taking corners more cautiously, as the car will not be perfectly balanced.

If you have a limited-slip differential (unlikely if your standard wheels are 14" steel, as usually only fitted to high-performance or off-road cars) then there is a possible risk of damage by using tyres with a different rolling radius on each side of the diff for a long period.

Answer 2

Hi, this is a cost cutting and perhaps also space saving excercise by the manufacturer. Your 14 inch spare will no doubt be a pressed steel wheel, rather than the more expensive alloy. It will also have a larger profile tyre, so that the overall diameter well be pretty much the same. This will mean that your ABS and other systems will not be adversly affected. It is perfectly safe to drive with this fitted, and will not cause any damage, however you should drive with more caution and limit your speed untill you can return to four of the same (At the earliest opportunity). Sometimes a tempory spare will have an advice sticker on it, failing that the max speed advice will be in your manual, Tom

Answer 3

14 Inch Alloy Wheels

Answer 4

15 Inch Alloy Wheels

Answer 5

I wouldn't put more than 50 miles on a spare of a different size. Remember spares are only used to get you where you are going until you can fix the flat. Never for long term use.
If your car is under warranty and something were to happen with the wrong sized tire, there may be problems with the manufacturer.

The car's suspension system should absorb the difference and I doubt there would be any problems at all for short term use.

Answer 6

No worries as far as mechanical damage, assuming you would replace the spare in less than a hundred or so miles. The smaller wheel size could throw off your anti lock brake system or traction control system, but these will both reset themselves once the proper sized wheel is replaced. All this is assuming that your car is equipped with these systems. The thing to be cautious about and to keep in mind is that with one out of four wheels a different size, the vehicle may brake unevenly, especially in a panic stop!

Answer 7

You should see what the profile off the tyres on the 15 inch wheels are and see if it is the same that of the 14 inch, if you have the same size tyres then you will have to replace the tyre on the 14 inch so that the total diameter of the 15" & 14" + Tyres match.
If not, you will damage the wheel alignment.

Answer 8

Always best haf right sizes spare, two is better, get tyre fitted when cheap then put on when needed. but if not easy to get Check how big the 14" tire is, put a chalk mark on tire and the ground, roll one revoluton, mark ground again then try with other size wheel.
You find 185/55 15 and 185/60 14 and 165/80 13 are all the same overall diameter or rolling radius, so there good chance your 14 would be hardly noticable if fitted. Dont even thingk abot using a space saver, I uses won on my FSO by Weston super mare and go rount almondsbury interchange by M5 and M4 it burst, lucky only do 150 kmh so dent beat out easy with hammer but lorry drifer wat I hitted into not hapy, had keep going Chippingham exit fore I dare stopping.

Answer 9

That would be your best option. It depends on the height difference as to whether you should use the 14 as a spare. What is the aspect ratio of the original (full size) 14" spare, as to that of the new 15".
If you are not familiar with 'tire jargon', it would be safer for you to just get another 15" to be safe. Do it soon, cause we never know.................

Answer 10

Many cars come with those toy spare tires. The general warning is that you can only use them for 500 miles at speeds under 45.

But thats more then enough to get you to a gas station unless you get stuck in the gobi desert .