Not true.

Handling and braking improves the higher the pressure.

 

I think that handling and braking performance are too subjective to measure under ordinary driving conditions. Only when we push the vehicle to the limits would any changes, good or bad, be observable. When most drivers do "push the envelope" it is usually for some emergency condition like avoiding an accident. Tough at that moment to be rational enough to measure things like g-force and stopping distance.

More importantly, and this cannot be emphasized enough in this thread, is to not exceed the maximum pressure listed on the sidewall of the tire and don't go under the vehicle manufacturers recommendation. Both conditions can lead to sudden failure of the tire with nasty consequences.

Safe travel is more important than economy or performance.

I run my tires at 38(rear) and 40(front). Recommended psi by Honda is 34 for both and max sidewall is 44. A fair compromise I think. In truth, I have not noticed any change in observable fuel economy in the six months I have made this adjustment from the Honda specs. Because I am a gentle driver, easy on the braking, accelleration, and speeds, performance changes have not been noticable.

 

Ok... try lowering the tire pressure to under recommended psi and you will see braking and handling suffer.

As for PSI and MPG. I too have observed no noticeable difference in FE from going from Honda's recommended psi to MAX sidewall PSI. But, I have noticed a noticeable improvement in handling and braking especially in the WET.

 

You are misunderstanding my statement. I'm not comparing pressure that is below a vehicle's recommended pressure, and what is advised by the manufacturer. Such lower pressure is never recommended or good. Tire performance would definitely suffer.

I myself, use the generally recommended 42/40 on my Prius with the original factory Goodyear tires.

I would never go higher than that with the factory tire, no matter what the potential milage gain. Yet I see others here recommending that.

I see that you are using high performance summer tires. And they are going to behave much differently than the factory tires, and certainly offer better performance in dry weather no matter what the pressure.

I, though, live in Duckland.

Lance

 

You are correct Lance.

The simple rules are:

1. Never inflate more than the maximum pressure listed on the sidewall of the tire.
2. Never inflate less than the vehicle manufacturers recommendation.

Everything else is both safe and fair game for experimentation.

 

This topic comes up again and again. Opinions are strongly held. But other than measuring tread wear patterns, we have not done the important experiments. Perhaps someone will set up an 'S-course' with traffic cones, next time a number of hybrid vehicles gather, and we can explore traction and braking vs inflation pressures on different tires.

I completely agree that safety comes first. Tire service life might be second, ahead of small changes in fuel economy, based on a 'cents per mile' analysis. Without compromising safety, controlling operating costs is a most sensible goal.

DAS

 

I am not misunderstanding your comment, I was just showing you an extreme.

You can improve handling by bumping up your psi but you will get a stiffer ride.

 

Then let me say that this very broad generalized statement that you have made here is clearly false, and certainly not true for all vehicles and tires.

You can definitely get more than just a stiffer ride with over-inflated tires. Reducing the tire's resistance can adversely affect steering, and I'm confident that the effectiveness of braking would be less as well. I clearly noticed a much more difficult time steering when I tried going to a higher higher PSI with my Prius and its factory tires.

Most people are NOT driving on performance tires, as you are. Performance tires are not cost effective for most consumers. They generally cost more, and have a much shorter tread life. Many offer no tread warranty of any kind at all, compared to very affordable tires on the market today that are rated for 40,000, 50,000, even 60,000 miles.

I even took a look at the Sumitomo tire that you mentioned earlier that you use on your Honda. But I found that it is not even made in the tire sizes used by either the Prius, or the Prius touring edition. So the tire you are using is not even available for any Prius owners to drive on.

Perhaps for your own particular car/tire combo, your statement is indeed true. But to claim that it is some kind of general truth that applies to all vehicles and tires is definitely not. You generalized statement is in no way accurate.

Lance

 

My so called performance tires cost less than the OEM tires they replaced. They wear a lot better than the OEM tires they replaced, they handle the rain as if it wasn't there.

In all my cars that I have ever owned, increasing psi improved handling (including braking) to the point that you could notice a difference. The difference is made clearer on rainy days.

I never exceed max psi, I never go below recommended psi. I play with the pressure until I find a point where handling is improved. As for mpg, I have notice no difference from recommended to max.

 

So called? Sumitomo themselves calls the HTR 200 a "High Performance Summer Tire". That sure sounds like a performance tire to me that is being marketed for summer use. They do not include it among their Passenger Tires.

You yourself indicated that you use the Bridgestone Blizzak in winter. So if the Sumitomo was such a great general purpose all weather passenger tire, then why are you using different tires in winter?

The majority of drivers DON'T want to have two sets of tires for their car. It looks like this particular Sumitomo model is indeed affordable. But that affordability is going to be offset greatly by having to buy two sets of tires.

And as far as treadwear goes, I find it disturbing that so many performance tires are now on the market with NO WARRANTY on treadlife. And that is exactly what Sumitomo is offering on the HTR 200: ZERO WARRANTY on treadlife.

Perhaps you are comfortable with this, but many consumers simply don't like to buy products from companies that will not stand behind their products, and not offer any warranty on how long the product will last. I would certainly never consider this Sumitomo ( even if they did have either of the Prius tire sizes available in this model ), based just on that plain simple fact.

The last set of tires I bought for my previous Honda were rated for 60,000 miles. When I traded my Honda in for my Prius, the tread on the tires was still fantastic. I'm really not impressed with the factory Goodyears on my Prius, so I will most likely be replacing them early. But when I do, it will certainly be for tires that offer a treadlife warranty.

Well, my experience is very much contrary to yours, so I cannot agree with your broad generalization.

I think the only thing that we agree on here is that we disagree.

Lance