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Low Rolling Resistance Tires

Background – Low Rolling Resistance Tires

This is another personal adventure so strap on your seat belts and enjoy the ride. Let me begin by saying that while I am an advocate for environmental stewardship, I haven’t always been. When I turned 18 and graduated highschool I got a car. I spent a long time deciding what features were important to me personally when it came to a car. Like many 18 year old males a big engine with lots of power was obviously going to be on that list. I also wanted something with lots of interior space and that rode comfortably (not that sporty bouncy suspension). In the end I was driving what I now refer to as ‘The Boat’ because it drives like a boat.

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My 1997 model Ford Crown Victoria, luxury edition, is now 17 years old with 253,000 (80,000 when I got the car) miles and almost eligible for an antique auto tag. I’ll be honest I still love the car but it gets pretty pitiful miles per gallon of fuel (it feels like 10 mpg, but I measured it at 15). When I was 18 I complained about driving to Atlanta, GA because it was about 100 miles and ‘was expensive’ to buy gasoline ($1.09 a gollon). Today and triple the gas price later and I am wondering why I didn’t drive more places.

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Today prices fluctuate between $3.00 and $4.00 a gallon and being a poor, and environmental, person I am much more concerned with fuel effeciency. Now the other piece of the puzzle is that I have for about a decade now been the poster child for brand loyalty when it comes to my Michelin tires. Let’s just say there is no better tire in the world than a Michelin.

There are lots of important factors that go into a tire and a tire should receive the credit it deserves. When you are driving a car the only part of the car that has contact with the road surface (hopefully!) is the set of tires. A poorly designed tire will not grip the road as well as a well designed tire. A quiet tire is also important if you do not with to hear them humming as you roll down the road. How they perform in wet/cold/hot and other extremes is also important. Finally, how they feel when driving is important. Both my cars have Michelin tires and have for a decade and will continue to for the foreseeable future (unless the brand goes sour).

One day I was at a local retailer buying new Michelin Tires and they had a new product out ‘Green X’ which are low rolling resistance tires. These tires have their tread cut in specific ways and are made out of modified compounds which create the ‘Low Rolling Resistance’ property. What a consumer needs to know is that low rolling resistance reduces the resistance the tire receives from the surface when rolling. This is similar but different from friction and traction. Friction occurs when two objects slide against each other like sandpaper on wood. If you are interested in learning more about rolling resistance please click here to be taken to the Wikipedia article on the topic.

The Problem – Green X tires

The problem today is fairly simple: Are Michelin Green X (their low rolling resistance line) worth buying compared to another tire?

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The Solution – A bit more complicated

It has been a while since I looked at this (16 tires to be specific). Last time I looked at this my first concern was that these tires wouldn’t grip the road as well and might cause me to have an accident. After some research I determined that this was not the case and I purchased the tires. My personal experience driving them for over 100k miles and driving Michelin without the Green X technology for over 100k miles are that from my own personal experience I cannot tell the difference between the two when driving (traction, ride comfort, sound).

With that established Michelin tires (which cost more) have another awesome feature. They last forever, I have purchased Michelin tires which are rated for 100,000 miles of treadlife. For comparison of different tires there are a few pieces of information necessary to determine how to get the best bang for your buck.

  1. The cost of the tires being compared (make sure you compare the same size of tire as this can have a big impact on cost and not necessarily in a logical way).
  2. How many miles each tire is expected to travel.
  3. The cost of gasoline.
  4. The improvement in fuel effeciency from the Low Rolling Resistance Property (this variable is different from one manufacturer to another depending on the actual technologies used on their tire/tires)
  5. The base fuel effeciency of your car (if you don’t know this visit fueleconomy.gov for info on US automobiles).
  6. The number of tires on the vehicle.

According to information published by the United States Department of Energy’s – Alternative Fuels Data Center the average improvement from using a low rolling resistance tire is approximately 3%. Since individual manufacturer data (and individual tire data) is difficult to acquire the 3% value will be applied for calculations. The calculation are conducted in an excel spreadsheet. For my car I went to Tirerack.com and located the most popular (all-season) non low rolling resistance tire for my crown Victoria AltiMAX RT43 (T-Speed Rated) at $84 per tire rated for 75,000 miles. Then I did the same query but for low rolling resistance tires. The result was a Pirelli Cinturato P7 All Season Plus, a 70,000 mile tire at $111.00. Then, I added the tires I actually have on my car the Michelin Defenders a 90,000 mile tire costing $129.00. Finally, I added the best seller overall the Fuzion Touring (H- or V- Speed Rated), complete with 40,000 mile warranty for $67.00 per wheel.

tire comparison of low rolling resistance tires
Image of the excel spread sheet showing the savings

As can be seen over the life of the tires the Pirelli save $447.18 (purchase price of $444) and my Michelin tires saved $574.95 (purchase price of $516). In essence Pirelli is paying me $3.18 to drive their tires for 70,000 miles and Michelin is paying me $58.95 to drive their tires for 90,000 miles. I estimated that I drive 30 miles per day which is about 10,950 which allows the Michelin tires to save me about $80 in fuel per year. The average American according to the U.S. Department of Transportation drives 13,476 miles per year or 36.92 miles per day. Using the U.S. average mileage yields: $Fuzion = 3045.98, AltiMAX = $3016.06, Pirelle = $2955.08 and the Michelin $2946,87. Buying the more expensive Michelin Defender instead of the best selling Fuzion results in a total savings of almost $100 per year.

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Conclusion:

Like in previous articles it pays to do the math it turns out the low rolling resistance tires actually tended to save more money over the life of the tire than the purchase cost. Getting paid for using a tire that rides comfortably, grips the road like Velcro and doesn’t make noise is something that I can live with. A tire I liked better than the defender made by Michelin was the HydroEdge (at least here where we get 50 inches of rain a year) but they merged it with another tire to create the defender.

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The article tomorrow will focus on your behavior in the bathroom! Check us out at A Solution A Day.

Click Here for a link to the spread sheet, you may edit the highlighted fields.