Wind Susceptibility

Is there a silver bullet to making the Prius (mine is a 2011 but my GF has a 2009 with the same issue) less susceptible to winds and air turbulence? I've never driven a smaller car and assume the size/weight has something to do with it but at freeway speeds this car is constantly moving from stripe to stripe. It's a fight to keep it in the lane at 70mph on a windy day. On a two lane highway, passing oncoming big rigs requires finesse. I enjoy the car but driving at freeway speeds are something I'm having a problem adjusting to.

 

I got the rear sway on it's way and I plan to put the STB on tonight or tomorrow night. Not sure on what under car braces I'm going to do but I'll add them likely sooner than later if it'll help.

Tire pressure, I'll give it a try. I don't know what the tires have in them as I just went with whatever the dealer had in them when I picked it up. I can check them tonight and toy with them.

Thanks guys! Hopefully I can get some stability without having to lower the car or change out the tires. I've never had/used tires that last 30k+ miles. I'm used to ZR rated and large/soft all terrain on the SUV's. I'd never heard of LLR tires until after I got this prius. I thought getting more than 20k out of a set of tires was a marketing myth.

 

My Tahoe had some aftermarket wheels and tires that the previous owner had just installed. I got 20k on them before I traded it in and the fronts were worn down past the wear bars. They were some kind of Cooper AT tire but they weren't stock size. I read in the Tahoe forums that those Cooper's were horrible for wear life, moreso than the other cooper tires. I do not know, but there was no way I'd get another 2k out of them.

On my CTS-V I was getting 12k on the fronts and 10k on the backs. Some of that may have been attributed to my foot. That seemed to be the norm for me on tires for the last decade as I've pretty much owned sports cars.

 

I've been weening myself off of HP for some time. Sold the CTS-V last year and made myself get used to the exasperating acceleration of a 7,000+lb 4x4 Tahoe. After initially fighting desires to supercharge the hoe, I finally got enough self-control of the speed bug that upgrading passed. I miss the acceleration and power of my previous cars but at the same time, when people are flying by me at 90+mph I see how wreckless I used to be and what's really funny, driving 65-70, I complete the freeway portion of my drive in approx. 15min a huge time increase over my previous 13min speed educed trip. Today power for me is trying to accelerate without putting the HSI in the 'power' zone.

Acceleration wise, the prius far exceeded my expectations of what I initially thought it would do. I'm not winning any races but it will get me up to freeway speeds in a respectful amount of time, often faster than the cars merging in front of me. Surprisingly, from light to light, it's just fast enough to cut off the unsuspecting taurus or f150 who think they're going to cut me off.

 

A little update. Had to drive about 180 miles today with 150 at freeway speeds. The Tanabe STB was installed last night and it seems to have cut the wind susceptibility by seemingly half so it was a definite improvement. I'm not sure if it's because the STB makes the steering more crisp and steering can be adjusted with minimal wheel movement or it the brace actually stiffens the chassis? Either way, it makes a difference.

I'm having a problem finding my tire pressure gauge so I'll run buy one this afternoon. I haven't made any air pressure changes yet. When I get it changed I'll report back.

 

I thought I'd provide a final (likely final) update to this thread. Since posting the original message I've added a Tanabe Strut Tower Brace, Toyota TRD Prius Sway Bar, and I've adjusted the air pressure in the tires. IMO the car seems to be more stable on the freeway when the wind is blowing or where crosswinds are at play. I believe some of this involved getting used to the car but all-in-all the additional air and suspension parts did make a difference.

The dealer had 36psi in the front and 33psi in the rear. I changed it to 41f and 39r. The ride was a little more firm but overall not bad. No real difference on coasting or gas that I could tell.

As I stated the car feels much "friendlier" to drive at freeway speeds now. Obviously wind is still going to push the car, any car, but my Prius doesn't feel like it's jumping from hash to hash and when the wind pushes on it, it's a more 'normal' push instead of jerk. Hopefully that makes sense - it does to me.

I may do a chassis brace in the future but for now I'm pleased with how the car handles, rides, etc. Thank you all for the help and advice.