Some Hypermiling techniques denounced by AAA

[htvfd460]

But that does make a difference anyway. I will rub over smaller bumps over inflated, but bottom out with lower pressure.

For the diameter expansion relating to force of energy I think a good example would be take a kid and put them at the center of a merry go round. They won't fall off. But spin the merry go round at the same speed and let the kid move outward and when they fall off ask them witch position was easier to hold onto, the center or outer.

[NachtRitter]

Originally Posted by htvfd460

It will increase by the diameter's difference. My tires are about 27.5" at 28 psi. Setting the pressure to 35psi expands my (center tread) diameter to 29". My tires change by 1.5".

And how much additional stopping distance will this 1.5" diameter increase require?

[htvfd460]

At 5 psi over ford spec of 30 psi {I prefer 28 in the front now} I lost a good 15 feet at about 55 mph. I didnt go any further than 5psi under the max of the tire indication {40 psi}. But maybe it was just that they were continental conticraps, i mean conticracks.

[Frank Lee]

It crowns up and expands to a larger O.D.?

http://www.officer.com/web/online/Editorial-and-Features/Driving-Under-Pressure/19$27281

I shall have to measure that...

[NachtRitter]

Originally Posted by Frank Lee

It crowns up and expands to a larger O.D.?
...
I shall have to measure that...

I'm not sure he's saying that...

Originally Posted by htvfd460

I can't check ride height if the wheels aren't attached to the truck on a flat surface. I wanted to see the correlation between the tire height versus ride height.

and

Originally Posted by htvfd460

But that does make a difference anyway. I will rub over smaller bumps over inflated, but bottom out with lower pressure.
...

What I get out of these posts is that he's simply measuring the difference between the ride height and then making the assumption that the tire diameter is changing... so if the tires were under-inflated to begin with (28psi seems really low) and then they are pumped up, then naturally the ride height will increase... doesn't mean the diameter of the tire increases though.

[htvfd460]

I will go with the ford explorer with Roll Stability contoll for this example. When IDS is hooked up and I monitor the PIDs for the wheel speed sensors and set all but the right rear to Spec Psi and the RR tire to 3 psi above spec I will see a slower speed pulse at the RR in comparison to the others. The module takes this signal and interprets an error in the vehicle's predetermined dynamics and acetates either a breaking reaction threw the abs module or the 4x4 module. This happens because the tires diameter has changed by comparison to the others. It may not be a dramatic change to the foot print visually, but it is when calibrated to a constant differential calculation.
The crown Vics weigh alot for a car. This is due to it's chassis, Wich is comparable to a truck chassis in that the body can be removed and will still support the drive train and suspension components. PDs usually have maintenance thre bidding shops, the lowest bid wins. The shops keep cost down by using nearly own quality parts. Tires are within that element. Higher pressure does increase the force on the bead to hold it to the rim. Mahwah PD uses Goodyear eagles and Forteras Wich are OEMs. They are a strong tire. With the PD mentioned I am assuming that Dept hadn't been paying attention to pressures and it lead to a longer and more even pressure over time.
Try the chalking technique from OEM pressure to about 10 over sidewal on a truck or SUV. The results will be more noticeable on a wider tire with an 85% sidewal measure.
The part about hydro seems a little off for the example given. In that the ski would represent a slick bald tire. A good tread can have treads over 1"tall (murders).

[htvfd460]

Also with the Crown Vic with the police interceptor package. Bought as is are stock. The ones PDs get have to have an alteration sticker on them. Ford sells them as fleets to companys that alter them for police use. Added weight at different positions changes their dynamics completely. And each company uses different products, from galls to code 3 products. The suspension isn't altered for the increased load either. So some are heavier than others requiring a higher pressure to compensate for the differences made.

With my ride height, it only increased by less than half of the tires height as the pressure was increased. I measured the tires height on mine. On ecomoders I had to measure diameter on the ground before and after a 10 min or 10 mile (witch ever was second) ride for ford's warranty requirements.

[htvfd460]

After re reading when I posted about the 85% sidewal I realized I hadn't finished. Once that tire has been tested check a 40 or 50 series tire. There will be a difference.
An example from memory was another tech has a mustang with tires wider than stock but the same rim size, the sidewalks stuck out further than stocks. He dropped the pressure by 3.5 psi to prevent center tread deterioration. He was also hard on the throttle and went threw tires in 12000 or every 4th oilchange. He was a crazy guy but he knew how to get a car to hook up off the line.

[euromodder]

Originally Posted by htvfd460

There is a place that the locals arround here call 5 corners. 5 stop signs for each road for the intersection. It is always a big debate for students who are taking drivers ed in this county. {Sussex NJ} The signs were place there in responce to the ammount of accidents

Signs or traffic lights never stopped anyone from running them.
Short of a physical barrier, some people will run them no matter what the council puts up.

They're not the people that councils should be considering when putting up signs.

Having everybody stop wastes everybody's gas, so it shouldn't be done.

In Europe we most often use the Yield-sign .

The only difference to a stop sign, is that it doesn't oblige you to stop if stopping isn't necessary.

[euromodder]

Originally Posted by Frank Lee

By how much?

Dunno, but apparently enough to reduce the wear on the shoulders for me

Exactly the opposite of what the AAA claims.