Comments on: Are Tire Mending Kits an Ideal Replacement of a Spare Wheel? https://carspiritpk.com/are-tire-mending-kits-an-ideal-replacement-of-a-spare-wheel/?utm_source=rss&utm_medium=rss&utm_campaign=are-tire-mending-kits-an-ideal-replacement-of-a-spare-wheel Pakistan's Trusted Automobile Blog Mon, 06 Nov 2023 19:15:06 +0000 hourly 1 https://wordpress.org/?v=6.7.1 By: Spares don't come now bcz they became so big&heavy https://carspiritpk.com/are-tire-mending-kits-an-ideal-replacement-of-a-spare-wheel/#comment-14989 Mon, 06 Nov 2023 19:15:06 +0000 https://carspiritpk.com/?p=75545#comment-14989 Wheel size has been increasing with every generation of car.
It is a delicate balance as larger outer wheel diameter increases ride comfort whereas increase in unsprung mass reduces ride comfort. As technology has been advancing they can use bigger wider wheels which look good and offer better ride comfort as well as better grip and even then increase fuel efficiency.

Once upon a time Hilux used to come with tiny 12″ rims, now 18″ is standard. The width of tyre also increased from 5″ in older vehicles to nearly more than 8-inches now (195-305mm and above). All this means that the wheel which used to be only 3-4 kg in weight, now is 20+ kgs! With German cars, the minimum rim dia is >22″ these days. The 25+ kg weight fixed in the trunk can become a projectile in a car crash and can seriously crush the occupants. Hauling a 4 kg spare tyre compared to 20 kg spare tyre also took less fuel. As wheel sizes increase, the dead load of the spare tyre is also increasing. Moreover there are few drivers who can wrestle a 20-25 kg spare tyre and easily change it without a helper.
This problem was solved a bit by using undersized spare kit, which came with a reduced speed rating and reduced load rating. This doesn’t eliminate the problem that the wheel you’re taking off from the hub is going to be the full-sized one!

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