Prius Tire Tuning

What experiment was that?

You claimed that braking distance was unaffected. What experimental data do you have that led you to that conclusion?

Psssst: "The ABS worked and the car came to a stop" is not experimental data that leads one to conclude that "braking distance was unaffected".

One of the useful things a troll does is provide a way to introduce more facts and data. In this case, how a small, donut spare tire can work without causing the car to run into the ditch when the brakes are applied.

The small tire works because the ABS modulates the braking force to keep the tires from locking up. They stay just at the verge of lockup which gives very close to the maximum braking force. Otherwise, the first time someone had to stop with a donut spare, it would lock up, the other would still be turning and the car would swerve. Instead, the ABS balances the braking per wheel to keep the car straight and controllable regardless of tire or wheel size.

But as for my bitch, if he were not a sociopath, we would observe:

o 'Elmo' is too lazy to run the experiment o 'Elmo' is too cheap to hire a 3d party to run the experiment o 'Elmo' is too poor to hire me to run the experiment

But a sociopath uses words to manipulate others and that is what we have here. Fortunately, he is so my bitch.

Bob Wilson

You claimed that braking distance was unaffected. What experimental data do you have that led you to that conclusion?

Psssst: "The ABS worked and the car came to a stop" is not experimental data that leads one to conclude that "braking distance was unaffected".

...for the tire in question.

Elmo doesn't have to run the experiment. YOU made the claim and left it hanging out there; the public wants to know, HOW do you know what you claimed?

It's a simple question, really, one that you've worked overtime to dance around.

How do you know what you claimed?

Psssst: "the car stopped" does not speak at all to "braking distance is unaffected," which was your actual claim.

Why are you refusing to provide data to back up your claim?

Why are you INSTEAD working very hard to twist this into "it's everyone else's job to provide the data" for your claim?

Ah. So you admit, you are a sociopath.

That's progress.

This morning as I was driving into work, I realized there is a way I might do some stopping distance tests and share the results for free.

I have a number of projects on my 'fun list' and one of them is an optically based, collision avoidance, automatic cruise control, and lane following system. The collision avoidance needs to know the stopping distance under a number of different conditions. So I would have to measure the stopping distance to make sure the safety zone is larger than the stopping distance. A fun project, it joins a queue of projects in my "job jar." So when this particular project reaches the top of the queue and I start work, I'll be happy to share braking metrics. It is not needed for 'Prius Tire Tuning' the subject of this thread.

We already know the ABS is working perfectly with these Sumitomo T4 tires. ABS moderates the braking force to be very close to the optimum braking force by measuring changes in wheel rotation of the tires. Furthermore, these tires with a 4/5 Consumer rating for stopping on dry pavement. Finally, the physics tell us that braking distance is not a function of tire diameter but only the coefficient of friction.

In engineering, we say, "GOOD, FAST, CHEAP, pick two." Without funding to change the priority, your request for data will have to wait . . . "NOT FAST." So once again 'Elmo', you are so my bitch. Still it may help to let folks understand my current Prius projects:

These are the projects I'm actively working. I have a longer list of projects in various states of suspense. So if you want a braking distance measurement but are unable to pay for it or too lazy to do it yourself, then you'll just have to wait ... 'Elmo' my bitch.

Bob Wilson

You at least are consistently dumb. You keep saying the same thing over and over, in the hopes that the more you say it the more likely it will happen or be true.

That's not the case, but you keep trying--and proving the very definition of insanity.

Remember, Bob, you were the one who brought up not only tire diameter but also width. Tell us again what braking distance is a function of.

Go ahead, we'll wait.

Nothing has changed and this is the answer.

Which you dispute without facts and data.

The title of the thread is "Prius Tire Tuning" which means how different Sumitomo tires affect handling to improve vehicle stability and modify the hybrid vehicle speed range.

We can only hope. My answer has already been posted, expanded, and now you've quoted it. Until I start the accident avoidance project, this is the only answer you're going to get for free. If you want to have braking distances measured before then, you have options:

(1) hire someone to measure braking distances (2) make your own measurements (3) hire me to make measurements (4) whine about it

You are so my bitch.

Bob Wilson

wow, you really are that dumb.

Amazing.

I can't wait for the next installment of, "Bob makes a claim and then demands that everyone else either believe it or prove him wrong".

Or, "Bob makes a claim and then uses jibberish to back it up."

We already know the ABS is working perfectly with these Sumitomo T4 tires. ABS moderates the braking force to be very close to the optimum braking force by measuring changes in wheel rotation of the tires. Furthermore, these tires have a 4/5 Consumer rating for stopping on dry pavement and the physics tell us that braking distance is not a function of tire diameter but only the coefficient of friction.

Still, I still so enjoy your whining my bitch.

Bob Wilson

You have managed yet again to completely ignore what you started with: tires of not only different diameters but also different widths, and your claim without data that "braking distance is not affected".

And then you continue to say that "ABS works, which means everything's fine" and then leave it at that. Data? You don't need no stinkin' data. You have DECLARED.

I can only imagine the circus music that plays while you type your uninformed drivel.

o Sumitomo T4s have a 4/5 rating from Consumer Reports (requires a login to access) but also an 8.1 of 10 in dry track braking from TireRack:

o Tire Rack, Consumer Reports, and the National Highway Traffic Safety administration use ABS engaged braking in their tests:

Bob Wilson

What does that have to do with backing up your claim that "there's no difference in braking performance"?

You could put bald ten dollar tires on their, and ABS brakes would work just fine--doing exactly what ABS is designed to do, let the tires grip to their limits.

Your continued cry of, "ABS brakes work just fine"--not just once, but over and over and over again--as your "data" to back up your claim that "there's no difference in braking performance" is absolute proof of your insanity.

What's hilarious is, even Al and his buddies recognize this by now.

What does that have to do with backing up your claim that "there's no difference in braking performance"?

I don't want to measure stopping distances. I simply want YOU to back up YOUR claims that "stopping distances are unaffected".

You've thrown out the allegation, now prove it.

You can't, or won't, or whatever. And yet for some reason, you continue to insist that you don't need to back up your allegation with actual data. The fact that you allege something is all the world needs, eh, bob?

You are so my bitch.

Bob Wilson

I was checking something else out and was amused to find this thread over at PriusChat.com:

Bob Wilson

There are many more like that, so much so that aftermarket strut brace and flex plate/crossmember upgrades are available to stiffen the suspension.

Other than your earlier post, I've never seen mention of neutering the problem via front-rear tire width differential or stagger.

I knew the NHW20, 2004-09, had a stiffening plate that improved their handling but I never saw anything for NHW11, 2001-03.

Actually it is the diameter and it was only discovered by accident. I was trying to reduce rolling resistance so I had two different sizes of tires, front and back. The drive up to Madison had the smaller "stock" tires and the rears were the larger diameter ones I was testing. The surprise was after swapping front and back pairs, the handling improved.

BTW, as far as stopping distance is concerned, I found an interesting URL with a detailed analysis:

I ran a quick excel model and it looks like there is a slight effect if different sized tires are on the front and rear. If I've done my sums correctly, larger front tires and smaller rear tires will stop faster than the reverse because it reduces the angle theta. In effect, with the larger tires up front, braking is more balanced at the car tips forward into a more level orientation. With the smaller tires up front, there is already a dip forward and this will off-load the rear tires. Best of all, larger tires on the front also provides the observed, greatest, straight line stability.

So if someone wants to test this with an NHW11, they need pairs of:

To do it right, we would also want to quantify the improved straight- line stability. The first test that comes to mind would be a substantial mass mounted so it can swing from one side to the other ... say an offset, rotating mass in the trunk. This would induce a known force and we could measure the change but there are several equally valid approaches.

Improved NHW11 stability from larger diameter tires was just serendipity which is why I'm sharing it with the community.

Bob Wilson

Of course stagger is a diameter difference, usually cross axis not axial.

. . .

Hummm, I hadn't run into the term "stagger" used in this way. Is there a community that uses this term? I'm always interested in new sources.

Bob Wilson

Racers. mostly oval types.