Please help me beat a dead horse.....

Going from a 195 to a 215 or 225 would help immensely. The mileage won't be as good as the 195 15s but you came from driving a 15mpg corvette, it would still be a vast improvement.

 

What PSI do you have the tires set at? I would try increasing it a bit and see if that helps.

 

I would go all out and pump them up to the sidewall max, just to see if the issue can be remedied without buying new tires and/or wheels.

 

I'd skip the 16" wheels and move to a 17". I'd actually try the Prius Plus lowering springs 1st to see if it corrects the problem. If not, then try the Prius Plus 17" wheels. Go to a dealer to test drive a model.

 

Reading this string, I keep thinking about the 17" wheels that came on the Prius I drive. This car is rock solid on the highway. I can get up next to the 18 wheelers at 75 MPH and never feel any sway or wander at all. Even with a good cross wind, she still holds the road well.

Running OEM Ace 17" Wheels (only available through Gulf States Toyota Distribution Center) and Michelin Primacy's. Size is in my signature file below. This Prius is like night and day better than our previous Gen II Prius. It handles like a dream and is a joy to drive. I liked my Gen II, I love my new Gen III.

I too vote to go to low profile 17" and add the stiffening brace. That is "if" you want to spend money on her. Otherwise, pump the tires up and drive the car... Whatever you choose, be certain to keep LRR type tires on her. Your wallet and your MPG will be happier.

Best of luck to you,
Ron (dorunron)

 

Not sure what your experience is, but I get 18 mph average while driving mine around town, and 28+ mpg on the highway. I don't baby it either.

 

Explain please.

"Drifts?"

 

If you do not run 2 pounds less in you rear tires, try that and see if it helps!

 

Definitely keep the rear tires two pounds lower than the front unless you are running the low profile 17" tires. They run 1 pound less in the rear.

I have read where adjustment of the toe a little will help with the wander/drift. Can remember exactly which way to set it, but it can be tweaked. It might be the camber instead of the toe. Do a little digging here on Prius Chat and I believe you will find the information I am referring to. I think the post was done within the last 12 months.

Best of luck to you lester williams.

Ron (dorunron)

 

I believe it's the factory yokohama s33's that is the problem. I have them on my car and it wanders.

I drove my Co-worker's 2013 with Bridgestone Ecopia tires and it did not wander on the highway.

Go to the dealer and test drive a new prius that does not have the yokohama s33's on it and compare it to yours.

 

I've had no such issue. Do you drive in a lot of cross winds? That would certainly make any vehicle prone to it.

 

You must be on good roads.

The s33's like to follow grooves on the road which causes some wandering. My car is a 2014 purchased in April and it has been wandering from the start. The alignment was checked a week after purchase because of the wandering - it was within spec.

Some tires have this tendency. My car spends a lot of time on worn interstates in Atlanta where the car wanders. The car will not wander on freshly paved roads. Some tires can handle grooves and such better than others based on their tread pattern, design, and rubber compound.

 

The Prius is basically a high-tech, high mileage econobox. I bought mine for the mileage and that's what I got, a car that gets me to work cheaply. One of my personal accounts is over 5 hours away. Driving that far on the highway is less than inspiring. Nothing you do is going to make it compare to a luxury car.

 

I think every vehicle I've owned has some "wandering" when on grooved pavement. It's what happens. The "bite" of the groves makes the tires want to follow the grooves rather than go in the direction they are pointed. Being a motorcyclist, this is a common experience on any non-smooth road surface, so I'm used to it.

Out where I live, potholes are more of an issue than grooved pavement.

 

I think MSA14 is on to something as I have now arrived back home. Coming through Montgomery, Ala. on the way home--- I-85 is very ''rutted'' and the car was keeping me busy just staying more or less centered in my lane. We had traveled mostly 4-lane between Montgomery and Savannah, going through Columbus, Ga. and the roads were lots smoother--newer-- and the ''wandering'' was not near as prevalent. So--- ya'll are on to something here-- My G/F also commented, ''The Five is wider and does not follow or wallow in truck ruts like the hatchbacks'' leaving me to think wider tires would ''stabilize'' mine more also. The wonderful news behind this story is--- we averaged 56.7 mpg on the 1,171 mile trip, and that was running speed limit home, slower on the way up, A/C running both ways.

E.T.A.,,,Elsie is my G/F and a member here also, posting on her computer ]