I am getting a new 4runner! But I am planning to install new KO2, living in Canada where snow and rain is part of life, I am second guessing. Are they so bad that I should reconsider?
It depends on your expectations and your driving style. Are KO2's the best in wet weather conditions? Not really, but they're manageable if you're attentive to the road conditions, temperature, and your PSI. Not everyone is, and given other available options, those who aren't should shy away.
I think I've said this half a dozen time on this forum, but you should buy the tire best suited to your driving style and terrain/conditions, not for looks alone. Tires are the single largest and most expensive safety item on your vehicle, and are often the most neglected and overlooked.
That said, KO2's are a desert style tire built for Baja and similar other dry/arid terrains. You can tell this by looking at the tire's tread pattern and design. They are designed to grip uneven terrain...There are no straight channels for water to escape easily without causing some kind of float. The more water, the more chance of a loss of traction due to the inability for water to escape from under the tire. Most AT tires have this same issue but to a lesser degree, as their tread pattern generally has a straighter pattern running the circumference of the tire (Cooper AT3/ATP's for example).
Most everyone in here is just providing anecdotal evidence. Expedition portal did a fairly comprehensive test of AT tires on the market a few years back using the BFG KO's, among other competitors, and it was the worst wet weather performer and near bottom to mid range performer in all but one of the On-road scenarios (
Comparison Link Here). The tread design has not significantly changed since the original KO's, however the K02 did see slight changes in tread design, siping, compound mixtures, and shoulder protection leading to better offroad performance, but they still use the same basic tread pattern which is largely the biggest issue with wet performance.
You need to take into account that customers/forum members will make all sorts of mental leaps to rationalize their purchase for shame of being ousted for buying the wrong product for their situation (or they aren't using it in the way that you intend to), while on the other hand, others will go out of their way to bash a product for not meeting their expectations despite buying the tire based on reasons it shouldn't have been purchased (ie: wet performance).
The KO2 is a great tire, that is handsome and very popular on these forums and in general, but it's not the best tire for every situation... it doesn't matter how hard Joe Blow spouts off at how his have been fine for XX,XXX miles in rainy conditions, in the end it's just his opinion, and opinions are like a$$holes; everyone has them and they're all full of sh*t.
Research. Look for comparisons by independent groups with no vested interest in the product for which you're interested. Look for comparable data (skid pad results, slalom times, stopping distance, wet weather performance) not customer surveys (that's just more anecdotal crap). Do this and you won't have buyers remorse later.
I'll leave one last little nugget. If you plan on buying a tire, and wet weather performance is a big consideration... look at different racing series' tire options for wet weather. Tread designs for those are likely the best designs available for that given condition. F1 is a great example. Look at how the channels in the tire are designed to move water out and away from the tire. If wet weather handling is a major consideration in your purchase, you would be best suited to find a tire that employs similar tread pattern designs in their tire.
Edit: I'll leave this article here that also discusses the importance of tread patterns, compounds, tread depth, and air pressures
https://blog.tirerack.com/blog/bens-blog/best-tires-for-rain.
