I bought my Prius in January with 4-year-old Michelin Defender all-season tires which were starting to dry-rot. I always found it remarkable how well the car handled, “for a Prius” – very linear and predictable cornering, stable over bumps. I finally got to a marginal level of tread wear, and one of the tires stopped holding pressure, so I decided to get new shoes.

I shopped the Michelins against the General AltiMax RT43; it was $68 vs. $110 per tire, so I figured, why not, I don’t mind if I have to sacrifice some grip for that level of savings. The reviews on the Generals were generally good as well.

Holy shit though. I almost pooped my pants my first day driving on the new tires, when I hit a sizable raised bump on one rear tire mid-lane-change (NJ-21 I’m looking at you), and the rear felt like it was going to bounce into outer space. I’m chalking this up to a lack of sidewall stiffness; uneducated guess. In harder cornering over 50 mph or so, the Generals flex like mad, and you never know quite when that rebound is going to happen. I noticed that I was doing a lot more small corrections in steering as the tires squished around. It also makes for increased motion sickness.

I ended up invoking the 30-day satisfaction guarantee and getting the Michelins. I know that the impact of tires on handling is no news to Oppos, but I was flabbergasted that weaker tires turned a Prius from a remarkable if low-power little beast, into a nightmare at speed.