Best dual use tires for a newly addicted autocross junkie?
May 9, 2011 6:16 PM   Subscribe

What kind of all-season tires would be best to put on a car that is both a daily driver and used for autocross?

I did my first autocross last weekend and am definitely hooked. The car I am using is a 2003 BMW 325i (RWD). I am running stock class for now and the car will be in need of new tires soon. (due to normal ware and tear.) I don't want to invest in separate autocross tires and rims this year. The tires need to be all season as I live in Wisconsin. Any suggestions?
posted by empty vessel to Sports, Hobbies, & Recreation (17 answers total)
Oh damn, that's basically impossible. What do you care more about, longevity or performance?

Until you can get a second set of wheels (seriously, do this as soon as possible), I say get Michelin Pilot Sports. You'll save money in the long run if you can get a second set of wheels and tires. Those Pilot Sports aren't going to last long if you're using them for daily driving.
posted by spikeleemajortomdickandharryconnickjrmints at 6:21 PM on May 9, 2011

Hankook Ventus V12 Evo is the tire I would go with for this. Very affordabe, great grip, reasonable longevity.
posted by gatsby died at 6:23 PM on May 9, 2011

Actually, if you're going to get them now, you don't really need all season. You could live with summer tires, since you're going to wear them out before fall. In that case, I say Michelin Pilot Exalto PE2.
posted by spikeleemajortomdickandharryconnickjrmints at 6:23 PM on May 9, 2011
posted by gatsby died at 6:26 PM on May 9, 2011

Hey, I used to kill 60,000 mile tires in under 10,000 on my old Camry from autoxing. I might just know this one. :)

The answer you don't want to hear is: the tires you're looking for don't exist. Here's why. Good autox tires have a few qualities. They're quick to heat up, sticky when cold-ish, have short, stiff sidewalls and don't need much air. This allows them to grip well off a cold start and not flex much when underway so as to make repeatable grip. They do take what heat you put in them so that they don't wear away in chunks, and they especially won't roll over onto the sidewall. They do this by being made of soft rubber with big, meaty tread and not much gap between tread blocks (and what gap is there is shallow). All of these properties, btw, are in common with what you'd probably deem "summer" tires.

All-season tires, on the other hand, have deep grooves and relatively small tread blocks so as to allow snow and water and mud to "squish" around them. They also don't usually have very stiff sidewalls in order to give a nice, smooth ride. Most importantly, soft rubber gets slick when it's cold, so traction goes way, way down if you don't get heat into them. Which you won't in the winter.

All-season tires and good autox tires are mutually exclusive.

So here's what I'm going to recommend: buy the same tires you would if you didn't autox, and inflate the hell out of them when you race. Get some shoe polish to mark the tire, and set your pressures such that you don't roll over onto the sidewall under cornering (any old timer will be happy to explain this if you don't know what I mean). If you don't have a dedicated wheel/tire setup, you're probably a new racer anyway, and unless your class is very, very sparse you won't be in contention for a top spot anyway. Focus on going fast with no traction. Once you get fast with no traction, you'll be ready to make space in your life for some dedicated DOT race rubber and nice lightweight wheels and a trailer and my this slope sure is slippery isn't it?
posted by TheNewWazoo at 7:55 PM on May 9, 2011 [3 favorites]

Best answer: All season tyres are a waste of money, to be frank. The reason winter tyres exist is because summer tyres are unable to produce grip when cold and winter tyres are unable to maintain grip and reasonable wear in hot temperatures.

Basically, there's no middle ground; all-season tyres just suck in both conditions by comparison to the proper options.

Also, you will get especially crappy grip for autocross with all season tyres. These tyres will essentially become your dedicated autocross tyres anyway as they will be pooched by the end of the year - at that stage, buy some second hand steel wheels from Ebay and get winter tyres. Being as you will wear out your tyres (especially the shoulders if you are not paying attention to tyre pressures and track temperatures) by winter, then don't compromise your competition.

Do they sell Yokohamas where you are? Are A008R's legal in the US? They are great road/race tyres and may even last until next season if you put your winter tyres on relatively soon. After all, you don't need a second set of rims if you really don't want to. After a summer of autocross, your tyres will need balancing anyway - accelerated wear - so why not fit winter tyres anyway?
posted by Brockles at 7:59 PM on May 9, 2011 [2 favorites]

Oops, I didn't finish a thought. Soft rubber is very slick when (winter) cold, grips well enough to gain heat when at "typical" cold temps, and gets very sticky very quickly when heated. Your more typical street tires (that is, all season tires) don't change their grip much at all with heat but their absolute levels of traction are much lower even at their best.

This means that your grip with all seasons will be very predictable when racing and everywhere else. Grip with a sticky tire will be literally non-existant to the point of dangerousness when they're cold-like-in-October. I'm talking in extremes here, but this is true to lesser degrees for all points in the race-to-snow tire continuum.
posted by TheNewWazoo at 8:00 PM on May 9, 2011 [1 favorite]

Oh, and from watching that video, do not under any circumstances fall into the 'stabbing the throttle mid corner' technique. Unless you are using it to de-stabilise the rear to encourage oversteer, your throttle pedal should be a one-way valve that is applied once between apexes. Early throttle kills exit speed like mad.

Also, do some reading on weight transfer and understand the basics of dynamic pitch. It will all be useful stuff for your competition and much better use of your time than trying to find mythical tyres that will fill your requirements.
posted by Brockles at 8:02 PM on May 9, 2011 [1 favorite]

Just to camp in this thread a little more, if you don't overinflate your tires, you'll kill them in very short order. Doing so does reduce your total traction levels even further, but working within the restrictions of your question as posed, you'll want to run really, really high pressures (I used to run 50 psi on my Yoko Avid Tourings under my Camry).
posted by TheNewWazoo at 8:02 PM on May 9, 2011 [1 favorite]

I'm all for racing on a budget, but I think this is really stretching it. There is no tire that will hold up to a summer of autocross and then provide reasonable traction during a Wisconsin winter.

What about buying your summer/autox tires now, then using the next 6 months to scrounge up a set of cheap wheels to put all-season/snow tires on? I'm assuming that even in the BMW world you can find people trying to sell their factory wheels at rock bottom prices on internet forums. (Or get steel wheels with the tires already mounted and balanced from Tire Rack.)
posted by Max Camber at 8:43 PM on May 9, 2011

Response by poster: I did over inflate for the event to 40 and will procure the shoe polish if I run on these for the next event.

Thinking about getting a set of wheels and mounting the existing tire on new wheels, these tires have enough tread left on them for a few more events. Later this year or next, depending on how these hold out, I can pop for some proper autocross tires.

In the mean time I will get a decent set of all season tires for everyday. I don't take the 325 out when the roads are really bad, that's what the X3 is for.

Any thoughts on this approach?

Mrs. empty vessel is watching the slippery slope very carefully, thus the reluctance to spend too much at one time. She's been a good sport so far given the 325 is technically her car.

Thanks to everyone for the great feedback so far!
posted by empty vessel at 8:46 PM on May 9, 2011

Best answer: So buy some replacement daily tires early and put the current ones on the race wheels, springing for proper autox tires later in the season? Sounds like a winning plan, though paying to have the old tires remounted may cost a few bucks.

Now you just have to convince the wife to let you pull out the rear seats and dash. I mean, it is a race vehicle now!
posted by TheNewWazoo at 8:58 PM on May 9, 2011 [1 favorite]

Response by poster: @TheNewWazoo

I am looking at a place online that will mount the new daily tires on the new wheels for free, if I order them together. When it comes time to pop for the autocross tires I could have the autocross tires put on the new wheels and switch the daily tires to the OEM wheels. Hidden agenda here is that she probably won't want to drive around with the racing style wheels for very long.
posted by empty vessel at 9:09 PM on May 9, 2011

For what it's worth, most people just buy whatever cheap stock wheels they can off CL, instead of ordering new wheels. Most stock wheels compare quite favorably to good quality aftermarket offerings in terms of weight and specs, and there's no question that they'll fit. That's what I'd recommend you do. Unless, of course, you want some nice race wheels. :)

With that said, if you're going to order a tire+wheel combo, Tire Rack is the canonical choice. They're a huge sponsor of SCCA SoloII, and they'll ship you the whole deal mounted and balanced, right to your door. They have lots of reviews, and stock dedicated race or other sticky rubber that most places would have to special order.
posted by TheNewWazoo at 4:23 PM on May 10, 2011

Response by poster: Did some research. If I want to stay D Stock then I have 2 choices for wheels 17X8's or 16X7's. All the really good deals are on 17X7.5's. This gets complex and expensive in a hurry. Looking on CL the used stock wheels used are as expensive as the after market wheels. Leaning toward going with the new wheels as everything on CL looks pretty beaten up.

My only hesitation is that I am reading that the 16's may be faster than the 17's any thoughts on this?
posted by empty vessel at 10:45 AM on May 11, 2011

I'm not certain of the specifics of the 325i and can't really give you a recommendation on wheels, unfortunately. Wider tires often give better traction but are heavier; smaller wheels can allow you to run really short tires for improved gearing and stiffer sidewalls while saving weight. It depends a bit on the specifics of the tire/wheel combo and the car they're on.

Beat-up (scuffed, scratched, pitted) wheels are okay for racing, so long as they're straight. If you're going fast enough, nobody can see you anyway, right? I'd probably seek out a reputable BMW forum with a dedicated SoloII sub-section, or maybe talk to some locals to see if anyone has any wheel/tire recommendations for you. You may also be able to get 15" wheels, depending on the up/back-date rules (which have changed drastically since I last raced, so YMMV).
posted by TheNewWazoo at 5:59 PM on May 11, 2011

From what I see of autocross, big wheels would seem to be a disadvantage to me. Not least in that you can gear your car down by fitting a smaller rolling radius for better acceleration (hence 16" wheels would be better).

You really don't need much lateral grip as your cornering speeds are really low. Agility (change of direction) and acceleration would be more advantageous traits, so smaller wheels (still with low profile tyres for sidewall control) would work better, I think. You only need fat tyres when the power is high enough to spin them too easily (spinning them a little will help in agility in a 325i). I'd go for a smaller rolling radius than standard (maybe 10-15% less) and a middle of the range tyre width for the sizes specified by the manufacturer and see how you go. So one size down from the standard 325i tyre width size, maybe.

THEN, with the money you have saved on tyres, spend money on dampers (shock absorbers). They are FAR FAR FAR more important than an extra 10mm of tread width.
posted by Brockles at 7:06 PM on May 11, 2011

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