Has anyone noticed that a good gust of wind seems to move the Prius a surprising amount on the highway when going over 70mph? I've driven SUVs before that get pushed a lot more, but the Prius moves differently. It's almost as though the car is lighter a moment, shifts sideways a little then traction comes back. SUVs on the other hand would actually tilt the way the wind pushed them, and you'd need to steer to counter it.

I'm obviously wondering if that wing shape is causing the Prius a bit too much lift... .

 

The Prius is specifically aerodynamically designed for high efficiency so it will move through the air with greater control than an SUV.

 

I noticed it on an extended test drive on an open highway on a windy day, otherwise it was very agile with a smooth ride. The stability in wind was one of the reasons I went with the 06-HCH.

 

Yeah... it may do better than an SUV but that doesn't say much. The problem is a bit different from an SUV - it really feels like the car is lighter on the ground. Not actually lifted up off it, but less weight exerted, leading to less traction. That surely would help coasting mileage (extend it), but not so great for staying centered on the road.

 

Part of the problem is the large cross sectional area of the Prius but two tire related items exacerbate the situation:

1 - The OEM tires (GY Integrity - 185/65R15 in the US) have very soft sidewalls. Increasing the air pressure to 42/40 (PSI front/rear) does help here. Replacing these with better tires helps even more (I went with Michelin MXV4+ 'Energy Saving' - LRR tires).

2 - An accurate front end allignment also can help (neutral or very slight toe-in).

JeffD

 

I was driving with a friend last night and she said the same, that it's probably the tires. I'm told California has a habit of grooving their pavement strangely and for most tires at high speeds the tires find a groove and shift the car just a little bit back and forth, now and then, which is pretty close to what I feel. The car doesn't feel like it jolts somewhere it just sort of floats a little one way or another, now and then, at high speeds. So maybe it's as simple as the tires. How was the cost on those Michelin tires?

 

My Michelin MXV4+ tires were about $450 installed at BJ's discount (a large east coast warehouse club) on sale. They list at about $550 (4 installed tires) so they're a premium tire. Note that the don't have a long tread life, but with care (rotation, balance - both free at BJ's, maintained tire pressure, and alignment) will go 50 to 60 thousand miles before needing replacement.

Other tires can last 80 to 90 thousand miles, but will cost you some MPG. I am getting slightly better MPG than with the OEM goodyear Integrity tires taking into account the lower revolutions/mile (849 vs 855, which slightly lowers the readings of both the odometer and speedometer) of the new Michelins.

JeffD

ps: Try raising the air pressure to 42/40 psi first, its free and does help handling, MPG and tread life of the Integity tires.