Sumitomo HTR+ Review on a Mazda RX8

I was forced to start looking at potential replacements for the stock Bridgestone Potenza RE040 (225/45/18) slightly after hitting 25,000 miles on them. I was hard pressed by economic reasons to find the cheapest possible tires that would offer a similar or higher tread life (higher was better) and a decent level of performance on dry surfaces, as well as wet. I eliminated a few candidates before settling for the Sumitomo HTRs, namely:

So after a brief discussion with a TireRack sales guy, he recommended the Sumitomo HTR+. First I was hesitant to go for an all-season tire. I thought to myself "All seasons on the 8? No way! But slowly I realized that I didn't have much of a choice in the price range I was shopping in. And so I ended up shelling out my credit card to purchase a set of 4 Sumitomo HTR+ in 245/40/18. The rolling stock ends up being something close to 1% bigger than the stock Potenzas. In other words, no big deal.

My first impressions

I got the tires installed and the suspension checked and aligned at Christensen Tire, here in Richardson. In all, the entire install took the a couple hours. I immediately jumped back in the car and drove off. The first thing I noticed was the engine and exhaust note -I am running on a completely stock Mazda RX8. And I could actually appreciate the engine reving up and down over the tire noise. Let me take that back: What tire noise? So, the first impression was a nice one.

However, happiness only lasted one corner. The first time I had to turn, I noticed a tremendous mushiness(sp) on the steering. On my way home, I kept praying for the tire pressure to be extremely low, therefore giving that soft feeling. Well, tire pressure was not it, I checked all 4 cornerns and all 4 were pinned @ 39psi. The tires were actually over-inflated from recommended pressure. The responsible was obviously a very soft and tall sidewall. There is a superimposed photo of the Sumitomos and the Potenzas below. You can see that both tires have similar "total" height when mounted; however, the Potenzas had a slightly rounded sidewall, and a much better lip to protect the wheels. On the other hand, the Sumitomos have a straighter(sp) sidewall, which apparently robs it from stifness.

I will try and rotate these tires every 5,000 miles. Reason being, on the last Potenza rotation, the tires that spent the last 7,500 miles on the rear were badly worn out (evenly worn though). And I'd like to keep the Sumitomos in the best shape possible.

Miguel P. is a college student seeking an Associates in Applied Science, currently working full time in the IT industry. He has a passion for autmobiles, specially those powered by rotary engines. You can contact Miguel or read more material at MyRotaryCar.com