If a car tyrel had a thinner width would the car be more fuel efficient?

Question

If a car tyrel had a thinner width would the car be more fuel efficient?

Answer 1

Not necessarily

There are two general areas that determine the efficiency of a tyre. They are wind resistance and rolling resistance

Looking at the tyre on its own the greater of these is wind resistance. Rolling resistance plays a more significant roll the heavier the vehicle is.

As a vehicles speed increases, rolling resistance is not as important as Wind drag, and wind resistance becomes the more important factor.

Continental (A leading manufacturer of bicycle tyres) believes the fastest combination of tyres (on a bicycle) is to have a 19mm front and 22m rear. The rear wheel operates in disturbed air that lessens the effects of wind resistance. So they go for a wider tyre for the lower rolling resistance.

Referenced in this article. This article also address some of the things that effect wind resistance and rolling resistance.

http://www.cyclingnews.com/tech.php?id=t...

Now back to cars...

Most cars are not open wheeled. The wheels are enclosed in guards (fenders), which greatly reduce the aerodynamic forces that are experienced by the tyre. The shape of the whole car has the greatest effect on how much energy it will take to move it through the air.

The Rolling resistance of a tyre is determined mostly by the shape of its footprint (or contact patch). A thin tyre will have a longer thinner footprint than a wider tyre. A tyre uses energy when it deforms to make this footprint. A tire that deforms less will use less energy and therefore be more fuel efficient. Generally a wider tyre will deform less at any given pressure.

Tyre pressure also takes an important roll in determining how efficient a tyre is. Putting more pressure into a tyre will reduce the contact area of the tyre thereby reducing how much it deforms.  Of course reducing the size of the contact patch also reduces the stopping ability of the car. If the tyre is over inflated it will also increase the rate the tyre wears.

Which then brings me to compounds. Harder compound tyre wear better but tend to bounce the tyre over any obstacles (like stones). This means that the car's suspension needs to absorb energy. Often this can be more energy than if the tyre was a softer compound.

I'll call it quits here but hopefully this gives you some insight into the world of tyre design and selection. Rather a nerdy subject that I'm a little embraced that I know a bit about. (I used to race solar cars)

In summary

To select the best tyre for fuel efficiency you need to consider more factors than just width. There are quite a few things that need to be juggled to reach an optimum.  You also need to consider that cost of the rubber or panel beater's expenses may out weight the saving in fuel.

My experience fuel  improvements come from

A tyre with little tread (tread deforms and uses energy) (Slicks are best) (down side is they Aqua plane in the wet)

Running the tyre close to maximum recommended pressure

Softer tyre compounds (mould themselves to small irregularities in the road surface.) (down side softer wears faster)

More flexible sidewalls (Reduce the effects of larger irregularities) (down side may puncture more easily)

Best tyre width will be determined by the shape of the vehicle the more wind the tyre experiences the thinner. With more aerodynamic guards (fenders) then slightly wider.

Most vehicle manufactures employ tyre engineers to select tyres for their cars, they are usually pretty good at it. So if you stay reasonably close to the manufactures specifications, you should be close to the best balance of performance and economy.

Answer 2

Definitely.   Try riding a road bike, then a mountain bike.   It feels like your pedaling twice as hard and not going anywhere.

Answer 3

Yes, but be sure to read the last paragraph.  Fuel economy isn't everything.  Tire width is a tradeoff between fuel economy, handling, and comfort.

Cars that are designed for economy, like hybrids or electrics, have slightly narrower tires than cars that are not designed for economy.

You can't go too far with this without having bad effects on handling, safety, and comfort.  And you shouldn't put narrower tires on a car than the manufacturer recommends, you could easily overload them.  Cars with narrower tires need to be designed for it.

Answer 4

I think so

Answer 5

ditto bobs answer and I might add that keeping the tire pressure at max would also improve mileage but would make the bumps seem bigger.

Answer 6

it would be more fuel effiecent but you would trade of traction therfore causing more wrecks ( and hazardous matrials being spilled)