I have an '03 Honda Civic Hybrid that needs new tires. The dealer says the best tires, mpg-wise, are the all-season OEM’s that came with it which are Bridgestones (I think). But nevermind the brand - I’m more interested in knowing whether it can be true that an all-season can possibly get better mpg than a summer tire. This seems counter-intuitive since all-seasons are supposed to have a tread that can, at the very least, account for some light snow and ice. I.e., they have a tread that lends to more traction, which means more friction and decreased mpg. So wouldn’t a summer tire offer less tread/friction and greater overall mpg?
The difference between the two types is minimal. Some all-season tires don’t look any different than regular tires. Winter tires are where the difference is. I have Goodyear Wrangler AT/D2 tires on my truck and get good gas mileage with 4WD on an 02 GMC Sierra with AC and AT and a 4.8 engine. Highway is 18.6 when you get off the highway, fill up and get right back on. New England in January. Not really good evidence but all-season could mean very little and they are not snow tires.
There is no real “all season” tire. They are really “3 season” tires. They are slightly better in snow than summer tires, and as a result manufacturers have made them standard equipment. Since the CAFE mileage standards have to be met, OEM “all seasons” are quite good with respect to mileage, often at the expense noise, harsh ride and sometimes short wear periods.
Pure summer tires are bad in mud, light snow, and rain. My neighbor was one of the fist to purchase a made-in-Germany Volkswagen Passat; it came with Continental high speed German Autobahn tires, rated to run continuously at 100 mph. The tires were great on dry pavement, but deadly on light snowy and icy roads.
The dealer would not change them and my neigbor ended up literally throwing them away and installing Michelin all seasons. He did not want to sell them, lest the buyer kill himself at the first light snowfall.
So, your dealer is partially right; the tires are first and foremost selected for FUEL MILEAGE. Secondly, to keep Americans from killing themselves on slick roads, they have an all seasons tread which is a good compromise.
If you live in an area with lots of winter, you should of course invest in “winter tires” that are good in snow, ice and rain. The reason your new car does not come with them is that the gas mileage will be LESS than with the standard all seasons.
I own 4 season tires called Nokian WR G2’s. While not a pure winter tire very close and they can be used the other three seasons without worry of excessive wear. The dry handling is decent and the wet and winter handling is incredible.
Only in the deepest snow I think pure winter tires excel or a small set of winter tires on pure ice.
Interestingly enough these tires have a low rolling resistance.
Summer tires and all season tires yield about the same gas mileage in general. But there are differences from tire to tire and brand to brand in rolling resistance and other factors that contribute to fuel mileage. The OEM tires on your hybrid were tested and found to be good for gas mileage. If you are happy with their performance check with several places to get the best price.
Other tires from other brands maybe as good or even better than the OEM tire. Michelin makes a line of tires that are promoted a high gas mileage tires. You can do some research on a site that sells tires such as tirerack.com.
I.e., they have a tread that lends to more traction, which means more friction and decreased mpg.
Friction, or traction only consumes energy if there is lost motion or slippage. A high traction tire does not nessesarily have more rolling resistance than a low traction tire.
Rolling resistance comes from the energy used to flex the sidewalls and rubber hysteresis. High performance racing bicycle tires used by Lance Armstrong have super flexible sidewalls so that they consume a very minumum amount of energy when that sidewall flexes as it rolls over the road.
Hysteresis is the energy that is not returned when something like rubber is compressed and then allowed to spring back. A Superball is made of ultra low hysteresis rubber and bounces almost back to its starting point when dropped. A ball made of high hysteresis rubber will drop without bouncing, like a ball of clay. Hysteresis damps out vibrations in tires, ultra high hysteresis tires will not squeal when they skid, the hysteresis damps out the vibration that you hear as a tire squealing.
Snow traction is more or less the result of the tread pattern, and a tire’s rolling resistance is more or less the result of the tread rubber chemistry and the amount of tread rubber used. So, in theory, it makes no difference if you have a summer pattern, or an all season pattern, but it would make a difference if you compared these to deep treaded All Terrain tires.
However, summer tires are typically designed for better grip. The rubber chemistry triangle is: Rolling Resistance / Traction / Treadwear - you can’t get good values for one property without sacrificing one of the others (or both!).
So summer tires typically give WORSE fuel economy than All Season tires.
I agree with all you say, but I would add that modern winter tyres, as opposed to snow tyres, gain considerable snow/ice traction due to the rubber compounds used. It the end it is difficult to really measure any one factor as they are all interconnected.
Thanks for comments. Good to know. It also looks like summer tires don’t typically last as long as their all-season counterparts. Another poster (B.L.E.) mentioned Hysteresis. I assume an ultra-low hysteresis tire would be summer tires? I’m also guessing that because they are less flexible they would wear out faster.
The other piece of the puzzle I forgot to mention is that I already have snow tires for the winter that I use Dec. - March (I’m in New England), and then switch back to the OEM’s in April. But my OEM’s (all-seasons) are worn and need to be replaced. So, better to get replacement OEM’s as the dealer suggests, or look for something that might yield better mileage? I drive 100 miles a day for work, so I want whatever will get me the best mpg.
From what everyone’s told me so far, it looks like there is really no advantage to getting summer tires over all all-seasons, expect maybe for less $$.
The OEM's were energy efficient tyres. There are other brand energy efficient tyres as well. Check out TIreRack for some choice and owner feedback. I would suggest relaxing a little and don't focus on just the mileage part. Tyres need to be able to keep the car on the road and to stop it and help it go. Looking at only one factor could get you blind sided. Great mileage is fine, but sliding off the road because of a little ice can really spoil the moment.
Sounds like a good compromise for the average US driver.
“…I assume an ultra-low hysteresis tire would be summer tires? I’m also guessing that because they are less flexible they would wear out faster…”
Low hysteresis tires are low rolling resistance tires. Given the technology triangle: Rolling Resistance / Traction / Treadwear - then tires that have good traction are going to be HIGH hysteresis - and the same is true of good wearing tires.
Flexibility has very little to do with rolling resistance - except to say that tires with low inflation pressure (and therefore more flexiblility) have high RR values.
- AND -
Addressing the winter tire issue: “…winter tyres … gain considerable snow/ice traction due to the rubber compounds used…”
Most of the snow traction comes from the tread pattern. The additional sipes act like paddlewheels. The rubber compound difference is a lot for the flexibility at low temperatures - which helps with the paddlewheel effect - and not for its frictional properties.