Stability/Drifting Issues With Added Weight?

I'm wondering what tire pressure you are running, and what is the tread depth of your tires? I also am wondering whether you carried any of your camping load on the roof?

I recently traveled ~700 miles through Nevada during Memorial Day weekend, group of four plus the hatch was filled with luggage. Highway speed around 75 mph, and I did not notice any handling issues.

 

I would guess tire inflation, worn tires, alignment out of whack are where you will find a problem.

I've had my 2005 fully loaded on long trips . . . never felt a difference, except the added weight makes acceleration a bit slower.

 

I ran as high as 60psi with the integrity tires and seemed to do fine ... possibly because the tread was not deep.... but then I went to pirelli tires and I drifted all over the place with those tire pressures.... especially going around corners and high speeds... almost like I was tip toeing on the tops of the puckered threads.
I dropped to 40psi and now they do great now.... I haven't really noticed any difference in mileage... maybe 2mpg or so.. but thats from the old tires.

I think drifting all over the place is less efficient anyway and possibly raises gas mileage.... as well as increases the risk for a blow-out with the higher pressures... especially in the summer.

What made me a believer was when I simply drove off the edge of the road slightly going about 40mph and the edge of the asphalt was broken just a bit on a country road and my right rear tire blew... thats when I upgraded to better tires and was thankful it wasn't my front that blew.

 

We have taken several trips with four adults and climbing gear. We were packed in like a fraternity stunt, but the Prius handled fine on the highway. I'd look at the tires and tire pressure.

Tom

 

I would suggest that you may want to also look at the weight distribution. If there was significantly more weight towards the rear - this would make the front end light and it would tend to be unstable with the degree dependant on the amount of weight.

 

I wonder if you underestimated your weight?.. unless you guys are teenagers or very thin, most adults alone would add up to 600lbs for 3 people if not allot.... but assuming your right... gear can add up too if you have several bags.

I noticed your car was about 3 years old.. have you recently gotten brand new tires?
if so, check the pressures as already discussed.

This has been a long debated topic, but the BT stiffening plate did help my car for side winds and cornering.. I would think added weight would only cause one to appreciate its benefits even more.

 

I'd agree with Porsche998. Too much junk in the trunk. I've done that before, and found the headlights gave me a great view of the treetops, but not so good of the road. (Now that was an adventure, driving 1000km of mountain roads in the dark.) Next time, if you can manage it, try to put more of the weight up front and less in the back. Passengers, too, if you can find a delicate way to suggest the "full figured girls" sit in front.

 

Its about time I'm not the one who said something like that!!! :first:

 

Hello Everybody!
tbird77 I had the same problem, I went to the alignment shop and I adjust the Toe in to 0.05 on itch site for a total of 0.10. This solved my Stability/Drifting Issue with or without weight. I will also buy the BT stiffening plate.

 

ah, I can definitely see how that could screw things up... I didn't think of that, nor have I have noticed that issue, but I installed the plate early on... let us know if you notice an improvement with the plate.. especially at higher speeds going around loops on the freeway, or sidewinds, or curvy road etc.