2010 Prius feels unsettled on the highway

We couldn't use your car because you know all the bolt-on's you added.
But that would a fun day if we could ever get something like this going!!

The funny part of this thread is the OP does not even own a Prius !?! He just started a big long discussion.

IMHO, that crossbrace in the middle of the car is there for Side Impact force transfer.
How can that little thing in the very middle of the car do anything for the feel of the car's suspension?

Oh well, only one way to tell.... maybe someday at some big Get Together we could come to some group consensus.

 

We need one of those get togethers to be more centralized for everyone like in St Louis or sumthin in the middle of the country

Mike

Mobile on my SGH-i717

 

I paid closer attention to the wandering while driving today. What I found is that my steering wheel doesn't snap back to center like most cars I've owned. It will hold a set position if I move the steering wheel a little in either direction.

If I use minutes on an analog clock as a measurement, I'd say my steering wheel will stick at 2 or 3 minutes in either direction without snapping back to center.

 

The factory setup is very light on caster and toe-in, which reduce scrub and re-centering, but improve turn-in and MPG. Teach yourself to re-center.

 

..fear of bolt-on's?

 

No fear

That's what is cool about this car with all the bolt on goodies a fellow can buy

Mike

Mobile on my SGH-i717

 

I'm fully capable of re-centering and actually it's mandatory if you own a Prius. But if you look at something like a 6 hour trip there are probably thousands of small steering adjustments needed to keep a Prius in its lane, while on most cars it's probably fewer than half of that amount.

I guess the question is... does the Prius have enough adjustment to allow caster and toe-in to be added to negate most of the wandering? How would changing to traditional alignment specs affect mpg?

 

There is no castor adjustment so it would take modifications to adjust castor. The easy thing to try is to adjust your toe-in to the max toe-in in the Prius spec and see what happens. My guess is that as long as you aren't outside spec, you won't lose much MPG.

As WEOH said, it could also be rear toe.

You said the alignment is good, what are the front/rear toe, camber and castor numbers?

 

I don't find the re-centering tedious and would argue that many small adjustments serve to keep the driver aware as opposed to complacent, especially when used along with cruise control. Your preferences may differ.

More static stability (toe, caster, camber) means more tire scrub, more mechanical drag, less MPG (and more rapid tire wear).

 

And I'm just trying to say there is a difference between the bolt-on/strap-on's that serve a function , versus the ones that are for style or some other feel good purpose, and can not be measured.

Or picked out of a blind test line up....

 

No kidding.

Although having said that, I know for a fact that a few well-chosen and strategically placed racing equipment decals are worth at least 30 rear wheel horsepower...

 

I got those cool colored family stickers for my Prius. I got Mad Power now

Mike

Mobile on my SGH-i717

 

Air_Boss,,

Man, I would LOVE some rear wheel horsepower !!!!!!!!!!!!!

What stickers do you recommend?

 

Of course it's tougher to make RWHP work on the Prius, but...

Sunoco 260, NOS, and Redline Oil (engine, trans and diff) for starters.

Then add your choice of carb/injection, cam and header supplier. VROOM!

Finally, add a Koni (or maybe something more contemporary) to keep it planted.

So how does that feel?

 

Would that make a Prius an AWD

 

I'm on it, buddy.

And since I run Redline D6 ATF, I would not be a Total Poser.....

 

Deleted.

 

Good call! 10W50, MTL and 75W90 in the Roadster...

 

...and other than by empirically trying things out, how can we otherwise judge whether a "bolt-on" serves a function or some other feel-good purpose?

 

Ideally, it would serve both, no?