Summer? Winter? Or all Season? You be the judge.
There's a lot of discussion lately in the office about whether summer tires should be legal to use this time of the year. Some of us think even all-season tires are dangerous. Neither of those types of tires is designed for use in the bitterly cold, below-zero temperatures we've been experiencing here in Ann Arbor. Add snow to the mix, and things get downright scary.
I have the pleasure of living in a house whose driveway is so steep it sends pizza delivery drivers running scared. It's almost impossible to shovel, as even the snow blower can't climb it. (See link below to my Blog about the reality of living with this driveway in the winter).
We had three large, heavy SUVs in the office a few weeks ago, which sounded like a perfect way to demonstrate the difference good tires can make. One was a Chevrolet Suburban with winter tires, another was a GMC Acadia with all-season tires, and the third, a Range Rover Sport, wore summer performance tires.
Obviously this isn't a scientific measurement of hill-climbing prowess, since we used three different vehicles. But the tire sizes and vehicle weights were close enough that the results still illustrate a point. And those results accurately mirror my experience in trying to climb the driveway each day: Summer tires are useless in the snow, and while all-season tires are definitely better, they're still compromised. There is no substitute for dedicated winter tires.
WINTER TIRES: 2007 CHEVROLET SUBURBAN
Our Four Seasons Suburban proudly wears a set of 265/70-17 Bridgestone Blizzak DM-Z3s. It has proven nearly unstoppable in deep snow, and this experiment was no exception. With the electronic stability control switched on, the big truck climbed the slope without fuss. Moderate wheelspin was controlled at all four corners, and the ascent was straight and quick.
With the ESP switched off, the Suburban's climb was only slightly more dramatic. All four tires spun on the ascent, but directional stability wasn't an issue - the big truck just went where it was pointed.
ALL-SEASON TIRES: 2007 GMC ACADIA
Our Four Seasons Acadia arrived too late in the season for us to buy snow tires, so it's been tootling around Ann Arbor on its factory 255/60-19 Goodyear Eagle RS-A tires. Even though these are marketed as High Performance tires, they still earn the All-Season M+S designation, and so onto the hill it went.
It was immediately obvious that the Eagles had their work cut out for them. In fact, the GMC's stability control system didn't allow enough wheelspin to overcome the slippery stuff, and the Acadia ground to a halt less than halfway up the driveway.
With the stability control switched off and generous throttle applications, the Acadia slowly made it to the top - but it wasn't without drama. Tires flung snow everywhere, and the Acadia roared from one side of the driveway to the other as it fought for traction. We had to completely lift off the throttle more than a few times to keep it from hitting the bushes on the sides.
What was the most unnerving about the Acadia's climb is that while the Suburban's Blizzaks allowed it to stop in the middle of the hill, the Acadia's Eagles couldn't provide enough traction to hold it in place. Taking a break meant slowly sliding backwards down the driveway with all four wheels locked.
So while the Acadia eventually made the climb, there was a marked difference between its all-season tires and the Suburban's winter tires.
SUMMER TIRES: 2007 RANGE ROVER SPORT
It's not often you see a Range Rover stuck in the snow - or anywhere else for that matter. Their off-road prowess is legendary, which made it all the more amusing to watch as the Sport struggled to even make it onto the driveway, much less climb it.
There's nothing about the Ranger Rover Sport that makes it inherently less capable than other Range Rover and Land Rover models. In fact, it's just as tough - it has a locking rear differential, a dual-range transfer case, and a computer controlled four-wheel drive system that has multiple modes to deal with different kinds of treacherous conditions.
None of those things helped. The Sport was absolutely hopeless on the driveway. Low-range or high-range; stability control on or off; snow mode or pavement mode; full throttle or half-throttle; there was no way this truck was getting up the hill.
And forget about stopping on the slope. The big Rover would generally make it halfway up the hill and then come flying back down-backwards or sideways-with all four tires spinning and the big V-8 roaring. It was a spectacle for sure, but with the busy road below, it wasn't very safe.
Lay the blame on the 255/50-19 Continental CrossContact UHP tires. Like the Range Rover Sport itself, nothing is inherently wrong with these tires. They don't pretend to be snow tires, and their awful snow performance is likely not much different than any ultrahigh-performance summer tire.
Whether trying to move or trying to stop, the summer tires were downright dangerous in the snow, and when compared to the winter tires' performance, so were the all-seasons.
CONCLUSION - WHERE DO YOU WANT SO SPEND YOUR MONEY?
So many people drive on all-seasons (or worse) in the winter, under the impression that they're a sufficient substitute for dedicated winter tires, especially because they feel that winter tires are too expensive. We disagree. Every mile you put on your winter tires is a mile you don't put on your summer tires, so there isn't a significant per-mile penalty.
Moreover, a set of dedicated winter tires often requires a cash outlay that's less than a typical insurance deductible. Which would you rather lay $500 out for - a set of snow tires, or an insurance deductible after you're wrecked your car? We think the former is more appealing, so we outfit all of our Four Seasons cars with dedicated winter tires.
And if watching a Range Rover hopelessly nibble at a hill that a Suburban devoured in one bite isn't enough to convince you, we're not sure what else will. Drive safe.