Posted by Bob & Holly Wilson on December 25, 2007, 7:10 am
> You know, Mythbusters showed that . . .
Exploding truck tires, can be a hazard; breathing air from a tire
underwater doesn't work; and driving in reverse on ice is ineffective
tire traction improver. However, Gyenes and Mitchell have shown:
> http://hiwaay.net/~bzwilson/prius/pri_tire_010.jpg
> Tire inflation lookup table:
> kN/m**2 - psi
> 200 - 29
> 225 - 33
> 250 - 36
> 275 - 40
> 300 - 44
> 325 - 47
> 350 - 51
> 375 - 53
>
> http://hiwaay.net/~bzwilson/prius/pri_tire_020.jpg
> Speed lookup table:
> km/h - miles per hour
> 80 - 50
> 90 - 56
> 100 - 62
> 110 - 68
> 120 - 75
Bob Wilson
Posted by Elmo P. Shagnasty on December 25, 2007, 2:10 pm
bwilson4use@hotmail.com (Bob & Holly Wilson) wrote:
> > You know, Mythbusters showed that . . .
>
> Exploding truck tires, can be a hazard; breathing air from a tire
> underwater doesn't work; and driving in reverse on ice is ineffective
> tire traction improver. However, Gyenes and Mitchell have shown:
>
> > http://hiwaay.net/~bzwilson/prius/pri_tire_010.jpg
> > Tire inflation lookup table:
> > kN/m**2 - psi
> > 200 - 29
> > 225 - 33
> > 250 - 36
> > 275 - 40
> > 300 - 44
> > 325 - 47
> > 350 - 51
> > 375 - 53
> >
> > http://hiwaay.net/~bzwilson/prius/pri_tire_020.jpg
> > Speed lookup table:
> > km/h - miles per hour
> > 80 - 50
> > 90 - 56
> > 100 - 62
> > 110 - 68
> > 120 - 75
You didn't quote me all the way.
Mythbusters showed that tailgating a big rig truck definitely saves on
fuel.
So in addition to pumping those tires up to 1000psi to get crisper
steering and handling, in addition to the fuel economy benefits, you
should also be tailgating big rig trucks. As in, an inch or less off
your front bumper.
I mean, if your goal is fuel economy, do it up.
Posted by Bob & Holly Wilson on December 25, 2007, 9:07 pm
> bwilson4use@hotmail.com (Bob & Holly Wilson) wrote:
>
> > > You know, Mythbusters showed that . . .
> >
> > Exploding truck tires, can be a hazard; breathing air from a tire
> > underwater doesn't work; and driving in reverse on ice is ineffective
> > tire traction improver. However, Gyenes and Mitchell have shown:
> >
> > > http://hiwaay.net/~bzwilson/prius/pri_tire_010.jpg
> > > Tire inflation lookup table:
> > > kN/m**2 - psi
> > > 200 - 29
> > > 225 - 33
> > > 250 - 36
> > > 275 - 40
> > > 300 - 44
> > > 325 - 47
> > > 350 - 51
> > > 375 - 53
> > >
> > > http://hiwaay.net/~bzwilson/prius/pri_tire_020.jpg
> > > Speed lookup table:
> > > km/h - miles per hour
> > > 80 - 50
> > > 90 - 56
> > > 100 - 62
> > > 110 - 68
> > > 120 - 75
>
> You didn't quote me all the way.
I stayed on topic, "Optimal Tire Pressure" and ignored the rest. Perhaps
you might start a thread on tailgating.
>. . .
> So in addition to pumping those tires up to 1000psi to get crisper
> steering and handling, in addition to the fuel economy benefits,
>. . .
Posted on the sidewalls is the maximum pressure. For my Sumitomo T4s
that pressure is 51 psi. BTW, there is an essay by the Tire Rack:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=1
"Disadvantages of Overinflation
An overinflated tire is stiff and unyielding and the size of its
footprint in contact with the road is reduced. If a vehicle's tires are
overinflated by 6 psi, they could be damaged more easily when
encountering potholes or debris in the road, as well as experience
irregular tread wear. Higher inflated tires cannot isolate road
irregularities as well causing the vehicle to ride harsher and transmit
more noise into its interior. . . . "
This is something folks who live with bad roads should consider.
Fortunately, North Alabama is blessed with good roads that seldom have
potholes. With good roads and a morning commute that seldom exceeds 55
mph, I run my tires at their maximum pressure rating, 51 psi front and
49 psi rear.
". . . However, higher inflation pressures reduce rolling resistance
slightly and typically provide a slight improvement in steering response
and cornering stability. This is why participants who use street tires
in autocrosses, track events and road races run higher than normal
inflation pressures."
The reduced rolling resistance pays at the pump but the steering and
cornering stability is especially nice. I regularly take turns and
curves at +5 to +10 mph over what other vehicles can handle. For
example, one of my favorite curves is at:
34 42' 31.00" -86 40' 11.05" (use Google maps)
This curve is rated at 45 mph for most cars. But I enter it at 55-60 mph
on cruise control and don't blink an eye. Tailgaters often wind up
backing off quite quickly because they have to.
Bob Wilson
Posted by Elmo P. Shagnasty on December 25, 2007, 10:49 pm
bwilson4use@hotmail.com (Bob & Holly Wilson) wrote:
> > You didn't quote me all the way.
>
> I stayed on topic, "Optimal Tire Pressure" and ignored the rest.
Why? You're all about performance and mileage, and are happy to tell
people to PUMP 'ER UP! to get better mileage.
If you're all about getting better mileage, then let's get better
mileage. Pump those tires WAY up (and enjoy crisper handling and
steering as a bonus!)--but why stop there? Go ahead and tailgate those
trucks to within half an inch.
I mean, if you want to get good gas mileage and all.
In fact, pumping the tires up is small potatoes in the gas mileage game
compared to tailgating trucks on the freeway.
> The reduced rolling resistance pays at the pump but the steering and
> cornering stability is especially nice. I regularly take turns and
> curves at +5 to +10 mph over what other vehicles can handle.
On highly overinflated tires?
My fear is that people will actually believe you and try this crap that
you're trolling.
Posted by Bob & Holly Wilson on December 26, 2007, 2:34 am
> . . . Go ahead and tailgate those
> trucks to within half an inch.
Not needed. I like to follow trucks at a safe distance, +200 ft., using
cruise control. The other traffic will smoothly pass me and the truck
without a problem.
>
> I mean, if you want to get good gas mileage and all.
I drive an NHW11, 2003 Prius and have a recorded average of 52.6 MPG for
40,000 miles:
http://greenhybrid.com/compare/mileage/car/1506.html
> In fact, pumping the tires up is small potatoes in the gas mileage game
> compared to tailgating trucks on the freeway.
You may want to visit CleanMPG.com to discuss this technique.
>
> > The reduced rolling resistance pays at the pump but the steering and
> > cornering stability is especially nice. I regularly take turns and
> > curves at +5 to +10 mph over what other vehicles can handle.
>
> On highly overinflated tires?
No, just the maximum side wall pressure.
>
> My fear is that people will actually believe you and try this crap that
> you're trolling.
Actually, I prefer folks to give it a try. You can always go up to the
maximum sidewall pressure and take a little test drive. If you don't
like it, pull over and let the air out. Belief has nothing to do with
it.
Bob Wilson