Before we jump into low profile tires pros and cons, let us try and understand what are low profile tires.
If we take a close look at the tire size information embossed on the sidewall of any tire, we will be able to notice a two digit number called the `aspect ratio`of the tire. This is usually indicated as a percentage of tire section width. As in this example, the aspect ratio is 45% of the section width of 235 mm,(106 mm)sidewall height and referred to as a 45 series tire.
An aspect ratio lower than 50% of the section width of the tire is considered a low profile tire.
Introduction to low profile tires
Working hand in hand with vehicle manufacturers, tire manufacturers have come a long way with their research and development and introduction of better performing tires to cater for the ever increasing demands of present day drivers and vehicles.
The introduction of low profile tires have evolved over the years. A quick look at the illustration below will give us an idea where it all started and where we are today.
In recent years, it is not uncommon to find 45 or even lower series tires on performance road vehicles.
With the introduction of low profile tires, many vehicle manufacturers are already adopting such tire sizes as standard fittings on the standard rims. Should there be any necessity to plus size from the original standard tires and rims, please bear in mind that the following are 3 important interconnected parameters that must be taken into consideration. If one parameter changes, the other two will also need to be changed.
- Rim diameter
- Width profile of the tire
- Height profile of the tire
The rim diameter and the height profile of the tire together make up the total wheel diameter. This dimension is important and it must be always kept as original as recommended by the vehicle manufacturer. The speedometer and odometer on board is calibrated based on this dimension. This dimension is also critical for the proper functioning of the ABS(Anti Locking Braking System), TSC (Traction and Stability control) and the TPMS(Tire pressure monitoring system).
The following illustration gives us an idea of how total wheel diameter is maintained with change in aspect ratio and the diameter of the wheel rim. Notice that all 3 parameters are affected.
List of low profile tires pros and cons
- Improved steering feel and response
- Improved sidewall stability especially under braking and cornering
- Due to bigger wheels, there is room for bigger brake caliper.
- Minimal camber distortion during cornering
- Marked improvement in braking during dry weather conditions.
- Marked improvement in slip angle when subjected to side forces.
- Harsher ride,poor comfort level due to a stiffer sidewall construction.
- Accelerated suspension wear and tear
- Poor acceleration due to more rotating mass.
- More prone to aquaplaning during wet conditions.
- Susceptible to rim damage if deep potholes are encountered.
- Up sizing of rims may result in the increase of unsprung weight
- Comparatively shorter tread life.
- More expensive to replace a set
- Higher road noise level due to bigger rubber contact area.
While there is an increasing trend in the use and sales of low profile tires due to its better handling characteristics, it is interesting to note the opinion of drivers who have already had the opportunity to replace two or three sets of low profile tires on their vehicle.
Most drivers of regular road use vehicles are not willing to put up with poor acceleration, harshness in ride, poor comfort level and higher road noise level. The lower the profile the more pronounced are these effects.
Analyzing the pro and cons of low profile tires, it is clear to us that there must be careful consideration given before embarking on an expensive up sizing exercise with after market available tires and rims.
In the case of performance vehicles already fitted with low profile tires by the vehicle manufacturer, extensive testing and tuning have already been carried out on the suspension of the vehicle to take care of most of the negative points that was identified.
If you are not into performance vehicles, just on regular road use vehicles, you can still take advantage of the positive effects and minimize the negative effects of using low profile tires. Consider using tires with aspect ratio of 65, 60 or even 55. This category of tires can be considered not in the low-low profile range and therefore have acceptable levels of harshness, road noise and comfort level.
Please feel free to leave a comment or a question that you may have on this subject and I would be happy to connect with you promptly.