Prius C Road Handling Perspectives

Hey Everyone,

Newbie to the forum here. I normally don't post on public forums, but I thought this was warranted. I have some statements and questions as they relate to the handling of the Prius C. I am wondering if anyone else has had similar experiences? Please feel free to challenge what I post here as I am looking for an intellectual and objective discussion about this and to evaluate other perspectives.

Disclaimers:

1. These observations are solely about my 2014 Prius C One (the design/car), my opinion, and relate to a specific set of driving abilities, vehical and road conditions that may not be reproducable. I am in no way suggesting that this car or its related accessories is/are unsafe. These observations are intended to enhance public knowledge and safety as they relate to driving this design.
2. Vehicle weights were pulled from edmunds. (sorry I am too new to post links)
3. Hybrid battery weights were pulled from a prius chat thread. Search battery weights and it should come up. (sounds speculative, but only source I could find).

Expectations:

1. Not expecting a 20k compact car to have premium suspension given the cost of the hybrid system.
2. Not expecting high quality interior when paying for advanced propulsion technologies.
3. A compact car with a short wheel base won't handle the same as higher tier cars.

About me:

1. Around 300,000 miles driven. No tickets and only one minor accident.
2. Not a speeder. Yes, I fit the steroetype of a Prius that drives the speed limit (sorry coal rollers).
3. Family has mostly purchased Toyota's in the last 20 years. Minus a short two year, personal, stint with VW, which was regrettable. We are loyal to the Toyota brand since we have always been treated well from the car's dependability to the dealer network.
4. I really want a full size Prius some day. From my experience, I feel they are the most dependable car on the road.
5. I am meticulous about tire pressure. No sense in causing extra wear on the suspension and tires, IMO. I keep this car at Toyota's recommendation of 35 front and 33 rear with 2psi extra for winter temperature fluxuations.
6. I have my own tire gauge and check tread depth at least yearly.

About the car:

1. 2014 Prius C One. No extras.
2. Owned since Winter 2015.
4. Around 45k miles.
5. Brand new Michelin Grand Touring All Season tires as of ~42k.
6. Had the original Goodyear Assurance Fuelmax all seasons on from original purchase until ~42k.
7. The car is 2500lb curb weight.
8. The hybrid battery is reported to be 100lbs.

About the driving conditions:

1. I live in the upper midwest. This pesky global warming thing has been causing very strange weather patterns that are increasing the frequency of hazardous road conditions. Snow, full melt, cold front, ice, more snow, more melt, then ice again. Sometimes just freezing rain and lots of it when it does happen. Can't wait for winter to be over!

General observations:

1. It appears most of the cost of this vehicle is in the hybrid system.
2. The suspension is very firm. If you don't own one, and are considering buying one, take this into consideration. The suspension and tire size is great for city and low speed driving. On highways, you will feel every little bump and bad pot holes will rattle your teeth. I had a long 1.5hr morning commute at one point and I began to get nauseous from how bumpy my ride was at the posted speed limit of 70mph. I don't get naseous easily. I just stopped eating breakfast before I went to work. I wish I was exaggerating this because I love the car otherwise.

Handling observations:

1. Throughout the time I have owned the car it will wobble when taking a tight corner that requires full steering wheel deflection. I have attributed this to the short wheel base. Not sure if this is a manufacturing defect.

2. Earlier this winter I was driving on a highway in a 70mph zone. It was me driving (150lbs), front passenger (120lbs), and rear right passenger(100lbs). It was beginning to snow and the ground was cold; just a light dusting so far. Traffic varied between 55 and 65 mph. I decided to keep a longer than normal distance between me and the car in front. Cars were already in the ditch. We also had a happy braker in the line of cars ahead of me. During one of the braking episodes we lost about 10mph quickly. I had enough distance in front of me and I did not slam my brakes due to the conditions, but gave them about 20% pressure. Then, I hit an ice patch.

The car immediately began occilating rapidly. I am hesitant to say fishtailing because it felt more like the car was rotating about a center rather than the backend swaying with the front end more in control. I did not overreact, kept the steering wheel in check, no brakes or acceleration. As soon as I lifted the brake pedal the occilations stopped. Luckily, the cars did not continue to slow down and I had room to recover. This was with the Goodyear tires at 6/32".

3. I had an accident where I had a similar experience as #2, but decline to discuss it further at this time.


Analysis:

The handling observations made me wonder a few things about the design of this car. I have owned and driven pure gasoline cars of similar weight and I do not feel they handled the same way. Particularly, I am curious about how the extra 100lb permanent battery weight underneath the rear seats affects the center of gravity along the longitudinal (long) axis of the car and how heavy it is in relation to the engine compartment. This arrangement usually (but not always) means that there is a further aft center of gravity than a gas only car of comparable weight and configuration, such as a Yaris or Corolla. Without going into arm/weight/moment calculations, and since I don't have access to the arm and datum reference location information, this is only speculative as to how much it changes, which is key to understanding its handling and type of stability. I don't encourage any speculation. If anyone can provide a non proprietary source of this information, it would be interesting to do the math to find the center of gravity.

What is most important is what can we take away from these experiences so we are approaching hazardous situations in the context of the design of the car. Just like there are handling differences between a front wheel, rear wheel, and all wheel drive vehicle. There will be handling differences between a Prius, Prius C, and Tesla for example. The Tesla has the battery pack low and between the axles so weight is evenly distributed the entire length of the car.

I know now that I will approach certain situations with more caution than I did before, just to be safe. Even though I don't have enough information to prove the handling differences objectively. Sometimes experience can be the best teacher.

 

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Hi Sam,

Thank you for your reply. I specifically asked for objective conversation about this post. Not inflammatory statements. I considered not replying, but felt that I should clarify in case anyone is following the same lines of thought as you or I if I wasn't clear on my original post. This may or may not help do just that, but I felt it was at least worth trying. Sorry that I write so much, but it is just my style.

1. Unfortunately, I am sorry to say, it appears that you picked the parts of the story you wanted to hear and made an incomplete conclusion. I do not blame you. This is an unfortunate side effect of internet communication. It is the "everyone hears what they want to hear" phenomenon on steroids. Everyone has bias and we all see the world through our own lense. I sincerely apologize if I hurt your feelings about your Prius ownership. Again, I was going for an objective discussion about the differences in vehicle design as it relates to handling.

2. It is unfortunate that you automatically assume I am a terrible driver without knowing me at all. I have never had a speeding ticket in 14 years of driving and I follow all of the rules of the road. I am a commercial aircraft pilot and flight instructor as well, so safety when operating any vehicle is my top priority. This has been ingrained into me through years of training. In addition, reckless driving/speeding tickets, etc, can cause the FAA to revoke, or at least suspend, my very expensive pilot licenses. I am not saying I am perfect, but I am far from driving my car like a "mad man" on the roads. It is all about balancing and mitigating risk. Just being alive and in the world is a risk. Nothing is 100% safe, don't you agree?

To reiterate: In scenarios #2 and #3, I was driving under the speed limit.

The people that ended up in the ditch in scenario #2 could have been for a multitude of factors, not necessarily just because the roads were slick. It was merely a contributing factor. Accidents rarely happen for one reason (i.e. the tires could have been at 3/32"). It is a combination of factors, that under the right scenario, lead to an accident. In aviation we call this the accident chain and have intensive training about our personal conditions as well as external risks before a flight. One version of the personal checklist is IMSAFE. If anyone is curious and wants to learn more Google "IMSAFE checklist".

In scenario #2, everyone was going between 55 and 65. The roads were fine other than that ice patch I hit. Further brake tests later in the drive showed excellent traction. If there was no one else around I would have dropped my speed to 40-45mph. However, it is not smart to go 40mph in a 70mph zone when people all around you are going 15 to 20mph faster than you. Especially with slick roads and in Wisconsin (driver's aren't the best, as a generalization). To be extra cautious I could have dropped my speed below 35mph, which is the theoretical speed at which tires can hydroplane. But...

...that speed difference is dangerous on a highway and will cause more risk of an accident since people are not expecting that. You may not get into an accident, but you could have caused a pileup behind you. Everyone on the road, and in daily life IMO, should operate with full situational awareness. That means not just thinking of themselves, but how their driving habits are influencing the bigger picture. Also, everyone knows, or should know, that part of being a defensive driver is assuming the other person isn't paying attention. So the best risk mitigation is to maintain a reasonable speed for the conditions that is under the speed limit, considering traffic speed, and giving yourself plenty of room between yourself and the car in front of you. That is exactly what I did. You cannot control everything. Hitting an ice patch was unexpected, but I knew it was a possible, but low, risk. No human being is perfect. We do the best we can with the information available to us at the time. Anyone who assumes they know more than the person who was there is just playing armchair quarterback.

In scenario #3, the roads were dry with intermittent patches of dusty blowing snow.

2. You wrote, "Taking a tight corner with the steering wheel turned to max. is NOT a safe maneuver to be doing on public roads.". I feel you assumed this was on highways? If so, I agree, that is a very reckless thing to do! I am also not sure I would be alive and/or talking to you about this if I did full wheel deflection on the highway. Just saying.

I am not sure my writing was clear before, so I will clarify. I was referring to turning tight corners on CITY streets at LOW speeds. (context: not yelling/angry, just emphasizing). I had a corner in my previous city that the wobbling would be particularly pronounced. It required you to take a turn at a sharp angle, between 5-10mph, to an intersecting street that was an acute angle to it. I would say about 30 degrees. So essentially you were reversing direction by going up this street. i.e. Going south then turning north by north east or north by north west. This required full wheel deflection on the turn or else you would hit the curb. I posted about it because I thought it was odd behavior and wanted to know if anyone has had similar experiences.

Thank you again for your post Sam. You highlighted that my message may have not come across as intended. I hope this clears up the communication. For others reading this, please post only if you have something constructive and objective to say. Thank you.

 

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Thank you for your perspectives on this! You sound like you have more varied driving experience than I do. Most of my cars have been front wheel drive. Do you think the shorter wheel base is why I am experiencing more rapid occilations/differences compared to the longer wheel base cars I have driven? I am curious about the physics.