Also, post up where you're located. Warm rain in Texas is different than icy rain in Michigan.

 

[QUOTE=CKit,Feb 24 2010, 05:31 PM]Also, post up where you're located.

 

I agree with most of what you said, but this is incorrect. Summer tires necessarily have a smaller void ratio to allow more rubber to meet the road, while all-seasons must increase the void ratio to allow for water evacuation.

Now, I will agree that some summer tires are amenable to rain driving just because they have a very good tread design, but saying good summer tires have more grip in warm rain than any all-season tire is patently false.

 

Just keep in mind that you don't need to remember everything all at once. Take it in chunks as needed -- just like anything else.

Nope. It's entirely possible for your specific car to have issues but there are no "general issues". Stock alignment should be fine unless you need something more aggressive for tracking.

Don't assume that rain tires are a cure-all. You definitely have to adjust your driving in the rain.

Spend some time driving and getting to know your S before you go all out on "improving" it.

If the wheels aren't stock, possibly. Also, IIRC there are threads that cover how the stock tires aren't the same width as tires of the same size. Don't forget that there is a wheel & tire subforum.

 

The incorrect perception that Summer tires must suck in the rain persists! But it is TOTALLY incorrect, good Summer tires are *better* in the rain than all-seasons in warmer temperatures.

Tires in the "Extreme Performance" do sacrifice some void ratio and hence hydroplaning resistance, but not necessarily wet grip (more on this later). But there are plenty of Summer tires in the "Max Performance" category with a large void ratio for excellent water evacuation. These will generally offer greater warm-weather wet grip than all-seasons will.

"Summer tire" *does not imply* dry weather only, it does RAIN in the Summertime! There are many Max Performance and Ultra-High Performance Summer tires that are specifically designed to provide outstanding rain performance and resistance to hydroplaning.

Including the Goodyer GS-D3 Max Perf *Summer* tire:

That looks like about a 33% void ratio, HUGE.

Dunlop SP Sport 9090 Max Perf *Summer* tire:

*Plenty* of void there.

Contrast with these Ultra High Performance *All-Season* Dunlop SP Sport 5000 M:


*CLEARLY*, "Summer tire" does NOT necessarily imply less void ratio, less capacity for water channeling, or less resistance to hydroplaning.

What all-season tires *do* have that Summer tires don't is a lot of siping, little slits in the tread blocks that don't provide greater void ratio. These are great for cold weather and for giving more bite in snow/ice condtions, but they don't do squat for hydroplaning resistance and are the suxorz for warm-weather performance. Much greater tread squirm, and much more heat generated in performance driving causing the tread to go beyond its optimal temperature range causing loss of grip and ultimately leading to chunking.

You couldn't be more wrong here. I've driven on practically slick DOT R-compounds, serious performance Summer tires, and on UHP all-seasons in the wet/rain at the track, my impressions are:

In warmish weather (~45-50+), on a wet track with no standing water, R-compounds are faster (once warmed up) than the best-performing Summer street tires, which are much faster than the best-performance all-season street tires.

In medium-heavy rain, Max or Extreme Performance tires are faster than either nearly-slick R-compounds (which become quite sketchy) or UHP all-seasons.

Even in a total deluge, good Extreme Performance Summer tires like the StarSpec have PHENOMENAL grip, *way* the hell more than any all-season. The only caveat being hydroplaning resistance in standing water. But that's what good Max Performance Summer tires like the PS2, GS-D3, RE050A PP, F1 Asymmetrical are for.

Even the best uhp all-season tires SUCK at the track, period. In the wet at least they aren't as prone to overheating themselves and coming apart as they are in the dry, but still nowhere near as good as *good* Max or Extreme Perf Summers. If there's snow down, maybe, but then I'd prefer to be on Winter tires.


Another note straight from the track (and the street as well): Void ratio isn't *anything like* as important as tread compound for wet grip, aside from standing water conditions. Look at this tire (Hankook RS-2):

Pretty reasonably generous void ratio, no?

Now look at this (Dunlop StarSpec):

*WAY* less void.

But the RS-2's have CRAP for wet grip, and the StarSpecs have, by FAR the greatest wet grip of any street tire I've driven on.

When I first got RS-2s for the car, I did a donut in a wet parking lot to check out the wet grip, and the back end just FLEW around. When I had to replace the rears, I got StarSpecs. Trying the exact same maneuver in similar-temperature rain/wet conditions, I could barely get the back end to come around at all, I had to back off before even getting it ~1/3 of the way around as I was still getting tons of lateral grip and forward drive even while sliding.

At the Mont Tremblant in the rain, with ~1/2-worn RS-2s up front and ~1/8-worn StarSpecs in back, my normally sorta oversteery AP1 suddenly became the most hideously understeering pig I've ever driven on track! Not due to hydroplaning (there were only a few spots of water running across the track), but just due to utter lack of grip from the RS-2s on the wet track, and the absolutely phenomenal wet grip of the StarSpecs.

Long/short, while high void ratio is going to be good for hydroplaning resistance, tread compound is going to have HUGELY more to do with wet grip outside of standing water conditions. And Max and Extreme Performance SUMMER tires have much much softer/grippier tread compounds than the highest-performance all-seasons.

Anyway, hopefully we can get over the MYTH that serious Summer performance tires aren't designed with rain usage in mind, many of them ARE. And even some Extreme Performance tires with reduced void area like the StarSpec will give FANTASTICALLY greater wet grip than the best all-seasons in weather that's not downright cold, outside of deep standing water at inappropriate speed.

 

You bring up some really interesting points that sort of challenge conventional wisdom RE all-seasons versus summer tires with respect to rain.

I'm willing to agree with you after reading your argument, my only caveat would be in the case where you could potentially encounter standing water (warm weather or not). I'd rather have the best all-seasons in this case rather than the best summer tires, because the all-seasons (generally-speaking) will provide more hydroplaning resistance and evacuate standing water better.

 

Further to ZDan's post, here are results from two Tire Rack tests, one for Extreme Performance Summer tires, the other for High Performance All Season.


First slalom and lap times. Compare how the same tire gains time between dry and wet tests:

Summer:




All Season:




The average summer tire gained a little over a second and a half, or 5.4%, compared with its dry time.

The average all season gained almost 3 seconds, or 9.6% over is dry time.


Now braking:

Summer:




All Season:




Here the differences were even more dramatic. The stopping distance for the average summer tire increased just about 7 feet, or 8.7%, in the wet (if you exclude the outlier Kumho XS, it's four and a half feet, less than 6%).

The average all season took over 20 extra feet to stop, 24% longer!

 

another tire to consider, that is somewhat less popular due to its price is the mich pilot sport A/S plus. they are as good in the wet as any of the tires mentioned so far, and very good in the dry too. what sets them above the rest of the high performance tires IMO is the tread rating is more than double most of the tires listed.

another tire that is highly rated is the continental DWS. I can't say one way or the other cause that is one of the few tires listed that i have not personally run.


if you are curious as to what i spend my money on, it is the A/S plus on my s2k, on my prelude, and will be going on the sti when the stock tires are done for. price wise though, if you live in a place where there is no rain, the star specs are hard to beat, if you don't mind losing some ride comfort.

 

If the conventional wisdom is that all-season tires are better in the rain than Max Perf summer tires, I think it is misguided.

But I don't think it is the conventional wisdom for people who know tires. Here's what Car and Driver had to say about summer vs. all-season wet performance in a recent tire test: http://www.caranddriver.com/reviews/compar...omparison_tests
>>>
Summer tires are not designed to be driven in temperatures below about 50 degrees and certainly not in snow or ice. To us, they are about maximum dry-weather performance, with enough capability in the wet to get through a sudden downpour. So we skewed the results to favor the dry-pavement champs, giving double the weight to those tests, even though summer tires generally outperform all-season rubber in wet capability as well.
<<<

Here's what Tire Rack has to say about
Max Performance Summer
You want an unsurpassed blend of dry and wet street traction and handling and only the finest will do.

Ultra High Performance Summer
You want an outstanding blend of dry and wet street traction and handling.

Ultra High Performance All-Season
You want all-season versatility (including light snow traction) and are willing to trade some dry and wet traction and handling to get it.

I don't know why you'd think that. It looks to me like Max Performance Summer tires generally have about the same void area as UHP all-seasons, sometimes more. Also, the channels in Max Perf are much wider. Water is going to have an easier time flowing through fewer broader channels than through a greater number of narrower channels with the same cross-sectional area (tread depth is the same for Max Perf Summer tires and UHP all-seasons, 10/32", so that's not an issue).
[edit]Er, then again maybe not. With more narrower channels, the water doesn't have to go as far to find a path, could be more narrower channels is better. Call it a wash? (pun intended)

Max Perf summer tire 2nd highest-rated for hydroplaning resistance (GS-D3 is best-rated in this category, see it a few posts up^^^)
Eagle F1 Asymmetric


Ultra High Perf all-season highest rated for hydroplaning resistance
Continental ExtremeContact DWS


I don't think I'd bet against the F1 for ability to channel water and resist hydroplaning. And for sure the F1 will have better wet traction in 45+ temps.

 

I think I started this debate with my statement above.

Let me clarify - when I said I didn't like the wet weather performance of the "summer" performance tire I was referring specifically to the amount of hydroplaning that would happen with even a small amount of standing water. Roads flood quickly here because our storm drains suck and I was hydroplaning on everything. I wasn't referring to grip/slalom performance in wet weather because I just don't drive like an asshat in the rain, I'll never push my car to that limit on a wet public road.

If I were to buy a separate set of tires for track only I wouldn't worry about standing water because a maintained track won't have puddles, or at least you know where the puddles are and can avoid them. But for public roads where you don't know where the big puddles are, I'll stick with all seasons.

Am I some kind of tire expert? Obviously not. I'm just assuming that since the all season tires channel water and the summer tires didn't, that was the reason I stopped hydroplaning. I'll sacrifice a few 10ths of a second in the slalom if it means I won't hydroplane down the freeway.