--- title: "What Is Rim Width? - Car Knowledge - Spare Wheels Road Hero" description: "Find out what rim width is, how to measure it and what space savers of spare wheels you will need for your specific wheel rim width. Click now to find out!" url: https://sparewheelsroadhero.com/what-is-rim-width-car-knowledge/ site: "Road Hero Space Saver Spare Wheels" published: 2020-08-29 modified: 2020-08-29 language: en-GB --- # What is Rim Width? – Car Knowledge ![rim width](https://sparewheelsroadhero.com/wp-content/uploads/2020/08/rim-width.jpeg) Since the tyres have flexible sidewalls, a single tyre size suits a range of rim widths. The tyre width range defines the narrowest to the widest rim widths on which the tyre is intended to be installed over its tens of thousands of miles and years of operation. The thickness of the rim can affect the thickness of the tyre. A tyre mounted on a narrow rim would be “narrower” than if the same size tyre were mounted on a wide rim. Note: Due to the fact that the overall diameter of the steel belt radial is essentially determined by the steel belts, there is little, if any, change in the overall diameter of the tyre due to differences in the width of the rim. The industry rule of thumb is that for every 1/2 “change in the width of the rim, the width of the section of the tyre will change accordingly by approximately 2/10.” “The rim width range of the tyre defines the narrowest to the widest rim widths on which the tyre is built to be installed during its tens of thousands of miles and years of service.” For example, the tyre size P205/60R15 is measured on a 6.0 “wide wheel and this size tyre has an acceptable rim width range of 5.5” to 7.5 “width. The tyre has a section width of 8.23” (209 mm) when mounted on a 6.0 “wide wheel. If that tyre was mounted on all rims within its length, the average section width of the tyre will change as follows: Difference from Rim Tire Section Measuring Rim Width Width 0.5″ narrower 5.5″ 8.03″ Measuring Rim 6.0″ 8.23″ 0.5″ wider 6.5″ 8.43″ 1.0″ wider 7.0″ 8.63″ 1.5″ wider 7.5″ 8.83” Due to the various widths of the wheel used in the example above, there is an estimated 8/10 “difference in the width of the segment of the tyre when comparing the tyre mounted on the narrowest rim to the widest rim within its radius. This can have an effect on fender well and frame clearance when choosing available aftermarket wheels and tyre packs. ## Combined Size Tyre Rims In addition, some vehicle manufacturers have developed Original Equipment applications in which the width of the rim does not fall within the original approved width range of the rim. For instance: 1995 BMW M3 combined 235/40R17 diameter tyres on 17×7.5 “rims (which are 0.5” narrower than the narrowest 8.0 “wide rim of the size). Corvette C3 models combined P225/70R15 sized tyres on 15×8 “rims (which are 0.5” wider than the 7.5 “wide rim now indicated for the size). Corvette C4 models combined P255/50R16 sized tyres with optional 16×9.5 “rims (which are 0.5” wider than the 9.0 “wide rim now specified for the size). The rear tyre application for Porsche 911 GT3 cars during the 2010-2012 model year combined 305/30R19 rear tyres on 19×12 “rims (which are 0.5” wider than the 11.5 “wide rim indicated for the size). While outside the normal recommended range of rim widths, these applications comply with the vehicle manufacturer’s specifications. ## What is The Rim Width of A Space Saver? ![rim width of a space saver](https://sparewheelsroadhero.com/wp-content/uploads/2020/08/rim-width-of-a-space-saver.jpeg) Space savers often have smaller rim widths compared to the [wheels that are fitted onto the car](https://sparewheelsroadhero.com/how-come-car-makers-dont-provide-spare-wheels-any-more/) however Road Hero space savers are available for specific vehicles. You can search for your car make and model and purchase the [space saver](https://sparewheelsroadhero.com/road-hero-space-saver-wheels/) that is designed to be fitted to your car. They even sell specialist space savers like [EU space savers for Chryslers](https://sparewheelsroadhero.com/product/chrysler-eu/). ### Road Hero packages usually include: - Wheel and tyre - Lock - Wheel brace - Bags for storage and more. Where required, nuts, bolts, and spigot rings are also given. Within the storage bags offered, anything supplied with the Road Hero Space Saver Wheel and Tyre Kit can be easily packed away. Some new cars come only with puncture repair kits for tyres, instead of a full [spare wheel/space saver and tyre](https://sparewheelsroadhero.com/the-death-of-the-spare-tyre/). Many drivers would prefer a [tyre and a spare](https://sparewheelsroadhero.com/no-spare-tyre-no-problem/) wheel so they can get going again as quickly as possible, this is why Road Hero space savers and spare wheels are an essential in 2020. #### To take a look at our full range of spare wheels and space savers, take a look at our [online store](https://sparewheelsroadhero.com/shop/), you can select your specific car make and model to find the perfect spare wheel space saver for your car so you don’t have to worry about entering the rim sizes or guessing if you aren’t sure. Our team of dedicated team members will then prepare your spare and ship it out to you so you can drive worry free and in the knowledge that you have a back up wheel and not a faffy puncture repair kit if you get an unexpected flat. ## More articles you might like [All articles](https://sparewheelsroadhero.com/blog/) [general](https://sparewheelsroadhero.com/what-is-a-tyre-load-index-and-why-its-important-to-know/) 31 Aug 2020 6 min ### [What is A Tyre Load Index And Why It’s Important To Know?](https://sparewheelsroadhero.com/what-is-a-tyre-load-index-and-why-its-important-to-know/) The Tyre load index determines the overall load capacity of the tyre in kilogrammes. It’s one of the principles that you need to look at when buying new car tyres. Let’s take a look at tyre load capacity and safety risks inherent in incorrectly classified tyres below. What Is The Tyre Load Index? The tyre […] [Read more](https://sparewheelsroadhero.com/what-is-a-tyre-load-index-and-why-its-important-to-know/) [general](https://sparewheelsroadhero.com/understanding-replacement-costs-for-shocks-and-struts/) 13 Jul 2026 7 min ### [Understanding Replacement Costs for Shocks and Struts](https://sparewheelsroadhero.com/understanding-replacement-costs-for-shocks-and-struts/) Replacement costs for shocks and struts include the price of the parts, labour for installation, and any related wheel alignment or suspension work. Costs vary by vehicle make, model, axle location, and whether the repair involves shocks, struts, or complete assemblies. This article explains typical cost factors, signs that replacement may be due, and how […] [Read more](https://sparewheelsroadhero.com/understanding-replacement-costs-for-shocks-and-struts/) [general](https://sparewheelsroadhero.com/how-to-clean-your-tyres-wheel-maintenance-tips/) 1 Apr 2021 8 min ### [How To Clean Your Tyres – Wheel Maintenance Tips](https://sparewheelsroadhero.com/how-to-clean-your-tyres-wheel-maintenance-tips/) We always think of cleaning our wheels as a priority when it comes to detailing. For most of us, I think this is going to be part of the daily washing regime. I decided to step away from car wheels, though, and to take a closer look at how car tyres can be washed. You […] [Read more](https://sparewheelsroadhero.com/how-to-clean-your-tyres-wheel-maintenance-tips/) --- Source: https://sparewheelsroadhero.com/what-is-rim-width-car-knowledge/