max oem tire pressure

I guess then that I've been asking for "trouble" for well over 50K miles between my Prius and my other vehicles and haven't been answered with any trouble including uneven wear and/or handling. This includes numerous trip on interstates in 90F+ temps. I am by no means reccomending this to others but to say that the sky will definitely fall if I do is not necessarily true. Burst test pressures are in the 200-300 psi range.

 

I hope I never have one of you high tire pressure fans behind me in a panic stop, especially on a wet day. I don't like being followed by any Prius regardless of the tire pressure, since the Prius is one of the worst of current cars at braking. Road and Track measured the Prius DEAD LAST among 150 cars in 80-0 mph braking. Also DEAD LAST in handling, which gives little comfort being next to a Prius in an emergency maneuver.

So, pump up your tires to 50, 60 psi and beyond to save an MPG, but increase your following distance compared to other cars.

 

Exceeding the tire manufacturer's maximum tire pressure is both dangerous and irresponsible. In every traffic homicide investigation the tire pressures in all 4 tires is always measured. Significantly under or over inflated tires is a factor in determining what charges might be filed against you. It will certainly be a factor in the civil suit against you.

Diamondlarry: Do you know people who have smoked cigarettes for years and not gotten lung cancer?

 

First of all, there is ABSOLUTELY NO REASON to drive 80mph. Ever! How did the Prius do in a test of more responsible speeds?

Yes I do. I have known several.

I have never told anyone to do what I do. All I'm saying is, this is what I've done, and this is the results and experiences I've gotten. If you or anyone doesn't want to do that; don't. It's that simple. But please don't tell me that I'm going to be a danger when I clearly have never been. The evidence in my particular case doesn't show it.

 

The R&T data summary can be downloaded here:

Road & Track Magazine - Road & Track Data Hub (6/2008)

Not inspired to transfer the .pdf into spreadsheet for proper summary, but here's a peek

80-0 mph braking distances ranged from 186 to 256 feet, with Prius indeed the longest.

60 -0 mph braking: 105 to 141, Prius 135 feet.

Slalom speeds: 57.6 to 75.6 mph, Prius 61.1.

Skidpad "g": 0.72 to 1.12, and Prius lowest (capable of the least lateral acceleration)

Quite by accident, superg reported the 2 (of 4) categories where Prius occupied (or shared) the bottom. But based on Road and Track's note on what constitutes a significant difference in each category, I am inclined to say that one must spend quite a lot more for a vehicle that will do these things significantly better.

Tire inflations were not reported, so we also don't know if the Prius (for example) was optimized for tire traction.

 

superg,

what do you drive? and why do you drive it? and is their a forum for your car?

and why arent you there? You certainly dont like it here. You seem to hate our cars.


If this forum had the option to ignore members you would be my first.

 

It does! (And after one of my comments to you in a different thread, I suspect you'll add me on there too.

Go to "Quick Links" on the top nav bar, then "Edit Options". On the left you should see "Edit Ignore List". Clicky Clicky!

It works ok, except it still inserts "post from XXX here removed due to your settings", when I'd really rather just have them disappear entirely. (Possibly even to the extent of ignoring whole threads they start, but that's a different post/RFE.)

Happy browsing!

 

I certainly hope that superg continues 'baiting' on this topic, because eventually it will convince someone to deconstruct the R&T data, passenger and cargo volume data (from other sources), total ownership costs and other criteria that might be used for vehicle purchase decision.

Thinking about a spreadsheet where the user supplies their own weighting factor to each of the categories. This could be a very rational way to narrow ones choices at least. But I can't bring myself to do all the work, so yes, by all means, troll away and convince someone else.

BTW the Corolla did not make the R&T 2008 chart (do not know why) and the Yaris S was detectably better in 3/4 categories I mentioned. Not in 60 to 0 braking though. The differences are just about what one might expect for 700 lbs lighter vehicle on the same size tires.

 

If you go much above the max rated pressure of the tire, you risk exceeding the strain limit of the polyester cord which reinforces the rubber sidewall. If that cord weakens or breaks, or delaminates from the rubber, you risk catastrophic tire failure. It's not worth any extra gas mileage--if there is any.

 

I don't hate your cars. Actually I am contemplating a car acquisition and I am considering the Prius and other hybrids and comparing them to conventional options like the Honda Fit, Yaris and Corolla. Yes, I am dismayed by the R&T data showing how much performance was compromised in the Prius design brief. My daily commute involves 2000 feet of elevation change in ten miles on twisty roads in Colorado. I am curious whether Prius owners that live in mountainous areas are satisfied with their performance. I will test drive one, if I can, to know if the performance is acceptable.

To me it seems that the excellent mpg performance and hybrid technology "aura" has caused many buyers to effectively accept 1970-80's "economy car" performance, perhaps without really being aware that the performance is at that level. I wonder if Toyota offered a Yaris or Corolla with performance comparable with the Prius (with a smaller 90-110 HP 4 cylinder gasoline engine than they currently offer) how close it would be to the Prius in mpg. It occurs to me that the 1984 Volkswagen GTI, for example, was fun to drive with not much more than 100 HP and yet got 30+ mpg, and that was before advances in fuel injection and engine management. My other peeve is weight. The 1980's GTI, as well as the new Yaris and Corolla are several hundred lbs lighter than the Prius. I am not sure how much of that is the weight of the hybrid drive train. Sure, safety devices and conveniences have added weight, but that doesn't mean manufacturers could not invest more in "adding lightness".

I am aware that other hybrids have more balance between fuel economy and performance. Unfortunately they tend to be pricey, heavy and their mileage advantage over conventional cars is minimal.

Superg

 

Superg, by all means rent one a lot of the rental car companies now have hybrids. Also some dealers will refund a one day rental if you buy from them.

 

I've done a lot of mountain-curve driving in 2001 Prius, and certainly found its performance adequate. However I do not generally drive near adhesion limits, so we must await reports from someone with sportier tendencies. Starting a new thread on that subject is certainly an option, superg.

I will say that I changed from 175 to 185 width tires (same aspect ratio) and liked the cornering better afterwards. Few people suggest that Prius OEM tires are the best available in terms of wet/dry/snow traction. But apparently when we try to improve the traction, it often takes away a bit from fuel economy. That trade-off may be hard to avoid.

 

I don't think you are comparing apples to apples here.

You left out the difference in TQ between a Prius and a conventional engine without the batteries and at the same HP rating. Between the electric TQ and the "CVT" drive the performance level is actually closer to 140+HP if compared to a standard engine in an acceleration contest.

I believe it to be unfair to compare it to 70s-80s performance levels. If you mean shear 1/4mile or 0-60 then the Prius is much more comparable to the 1990s import vehicles. I've spent plenty of time at the local 1/4mile track to see what those older Civics and Accords were putting down for numbers. They were definately nothing fancy.

The Prius cannot be compared to a typical "econo-box". If you were to ride in and experience a Prius over a Yaris, Fit, Focus, or Aveo you would quickly realize the Prius is in a different class altogether. It is much larger than those cars and IMO a lot nicer. Have you ever sat in all of the cars listed? I have and it's pretty dramatic.

I'm no noob to racing and high performance vehicles and I do not feel like I've sacrificed anything with my decision to make a Prius my only vehicle. With the exception of a bit of freeway wandering I have no complaints concerning the Prius. I wouldn't even want to make it faster if it meant losing even 1mpg. That is just not the point of this car. Safety and fuel milage are the main point. The utility is just icing on the cake.

I'm not sure where you are getting your data but their milage advantage is much higher than a similar sized conventional car. Do not make the mistake of comparing a Prius to a tiny Golf or GTI spec diesel. The closest you may come is the new Jetta diesel but then you are still less in MPG than a prius and adding more pollution and at what benefit?

In the end if the Prius is not for you then that is completely understandable. Purchase some other very fuel efficient, low emissions vehicle and I'm happy if you're happy.

 

We bought our Prius for the overall capability, not as either a demonstration of our green ethos to our neighbors (we're conservative Republicans), nor, primarily fuel economy (though that was certainly a big plus).

We valued seating space, cargo capability, fit and finish, and more that are not remotely like the econoboxes you are mentioning.

If you don't value those, and are as dominated by performance measures such as skip pad lateral acceleration as your posts suggest, I rather doubt this is the car for you. But we are very happy. By the way, my three most recent rides are:

1975 BMW 2002
1987 BMW 325i
2002 Audi A4 1.8T

In several respects the Prius is clearly quicker than was my 2002 (admittedly one of the slower ones).

It is not so nimble, and certainly lacks the freeway passing lane acceleration of the other two. But I am not unhappy to drive it.

And I am horribly unhappy to drive any U.S. 1950s car, to drive 1970s econoboxes, and plenty of other cars.

I don't think we are all living in the fog of delusion you suggest, but I do suspect that we have a different priority of qualities in a car than you.

While we don't have mountain twisty roads here in Albuquerque, we do have thousand foot elevation changes in four miles (with the altitude ranging from 5000 to 6000 feet). The Prius gives no trouble for us there. Mind you, passing at speed on the upgrade would require much advance planning and a big hole, but that has never gotten in our way. And I learned advance passing planning while learning to drive in the 1960s. One of the family cars was a 40 hp VW bug. Now passing in that thing required planning verging on slingshotting (keep a couple of hundred feet behind the target, on spotting a vision slot start a full-throttle acceleration timed to reach the bumper of the target just when the vision slot opens, make the critical decision to pass or not then, don't take the foot off the floor until clear, and pray that the target does not decide to contest the pass). The Prius experience is nothing like that.

 

One needs to acknowledge that when one drives slow like grandma (rather than high speed diving into the corners), not only do you get higher mpg's ... your ratio of emergency handling requirements goes down exponentially. Thus, no need for low pressure / stickier tires.
I love my 46lbs psi and 60mpg's +
.