Date: Wed, 5 Oct 2005 00:26:16 +1300
Reply-To: Andrew Grebneff <andrew.grebneff@STONEBOW.OTAGO.AC.NZ>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Andrew Grebneff <andrew.grebneff@STONEBOW.OTAGO.AC.NZ>
Subject: Re: Vanagon Tire Guidelines Report
In-Reply-To: <004b01c5c8a1$33d64f20$fd23b38e@bc.hsia.telus.net>
Content-type: text/plain; format=flowed; charset=iso-8859-1
> (8) VW may have wanted to have the EPA recognise the Vanagon as a Truck
>for the simplest of reasons. Light trucks are held to much less stringent
>safety, emissions and CAFE standards than cars.
> (9) On this list there are people who have modernised their brakes,
>plenty of people who have put 2.2, 2.3, 2.4, 2.5, 3 liter motors in their
>cars, 175hp TDIs, turbochargers, more advantageous gear ratios and even 5
>speed gearboxes. They have improved their vans with oil coolers,
>transmission coolers and better A/C but I don't see you telling them "That's
>not VW spec. " All of these changes have been made to allow their owners to
>more safely and efficiently pilot these somewhat old fashioned cars we love
>on the highways and byways of the lands we live in. They are now better
>cars, though only worth $6000.
> Drop by when you are in the neighborhood and I'll let you take
>Dixie for a drive in the rain. :-)
Well-said. Agreed in entirety.
Our vans also probably have a lower stock COG
than a Crown Victoria... and utterly unlike the
latter, are designed to handle (which of course
is best aided by decent tires... which LTs are
not... and dampers, swaybars and wheels). The
suspension/steering rates & geometries are
designed for optimum handling on twisty roads.
LT tires are designed to carry heavy loads at low
speeds, with low accelerations (ie no hard
cornering) and to LAST LONG. Nothing else. They
are pure compromise. Good car tires these days,
on the other hand, are designed to handle first,
then to last as long as possible, with ride
coming after those. Fortunately nowadays good
tires last far longer than they did in the 80s,
when profiles began to drop (back then a plus-2
15" with 50% profile was radical).
Those who want to drive a truck, and drive it
like a truck, go ahead and fit LT tires. Those
with camper conversions would be wasting their
time on performance car tires... you would
seriously risk rollovers with the high COG
resulting from the poptop, stove, cabinetry etc
if you tried hard cornering. Those with passenger
vans or bare vans are the ones who would benefit
(quite possibly by living longer) from a set of
good car tires. And by good I don't mean bargain
Pirellis or Michelins, both of which are awful
and have very low grip.
Look at it this way. If your van cannot recover
from a sudden swerve maneuver, you may well end
up custard. Or strawberry jam. Because in hard
swerves with LT or cheapo car tires, you will
probably hit what you're trying to avoid, hit
something else or hit the scenery.
Note also that overall tire diameter has nothing
to do with the vehicle's stability. What it DOES
mean is that a larger-diameter tire touches the
road fewer times per road distance travelled than
a smaller-diameter tire, therefore flexing less
and generating less heat by internal friction; in
theory it may last longer, as excessive heat is
the enemy of tire (ever melted tires due to
speed? I have). Also it will tend not to fall
into holes a smaller tire will drop into,
therefore the larger unit will give a better ride
if the profiles of both are similar. But lateral
accelerations (cornering) won't care what the
diameter is.
When fitting performance tires it pays to go to a
larger wheel size to keep the rolling diameter as
close to stock as possible; this is to allow the
speedo to read normally (though any instrument
shop could adjust for any tire diameter). In the
70s & 80s it was the thing to go plus-1 or plus-2
tire/wheel combinations on cars fitted with stock
13" wheels eg Golf GTis; this means fiting 14 or
15" wheels with lower-profile tires. These days
16" wheels are quickly becoming "too small" and
17s & 18s are now common stock fitment.
If you can afford to have the speedo reset and
there is clearance in the wheelarches and
steering, there is no reason at all as to why you
couldn't increase the rolling diameter of the
tire. Has anyone tried fitting 17 or 18" wheels
and 65% tires to a 2WD T3?
> The load rated tires on the vanagon are there for reasons. The safety
>requirements for the vehicle and to meet NHTSA rules on safety for gross
>weight. Note that the vanagon base tire rule also is actually a german
>safety rule as well. At the time of the vanagon there was no real advantage
>to getting LT rating for CAFÉ as the vehicle was a light truck under the
>rules any way you configured it. To get any kind of exemption it would
>have needed a (legal) gross weight capability of 8500 lbs. (at that time an
>exceedingly rare vehicle that wasn't a commercial truck, now the hummer and
>others fit that exemption)
Since when are the safety nazis experts? The US
legislators know nothing, but they pass laws...
often insane ones. And unfortunately other
governments quickly follow.
>I have experienced my vanagon with a load and standard tires and will never
>do it again!
>Also another reason...
>Many years ago I was driving a light cargo truck that had a load and
>standard tires. Took low speed sharp turn and almost lost the truck. Yard
>boss that witnessed it said he thought the tires were going to fold right
>under it. He had several complaints on the vehicle handling and after
>witnessing my incident he looked at the tires and then referred it to base
>safety and motorpool inspection section. The tires had just been replaced on
>that vehicle and the rest of the fleet by an off base provider for those
>vehicles because they were under contract rather than Air Force owned. The
>specified tires for the vehicle were C rated minimum but the contractor had
>replaced with standard tires without checking the specs (or just trying to
>cheat the contract). OSHA (don't know why), NHTSA, and Air Force safety
>investigated. The contractor was fined by OSHA (never understood that one)
>after the NHTSA and the Air Force investigations found that the tires were
>not just out of spec but a gross violation of basic safety. At the time the
>contract for the vehicles was under consideration for expansion. It was
>cancelled instead. (purchased more dodge rams)
What tires? Your argument has no point, as these
are unspecified tires and were probably cheapo
rim-protectors.
>Changing of spec to tighter is many times encouraged. To change specs to
>lesser is usually a violation of safety and/or laws. In some states it is a
>heavy fine to have under spec tires on and most you qualify for a small
>ticket (if they bother to check the tires). In all states if you have an
>accident and it is blamed on under spec tires you may kiss your financial
(and possibly legal) bottom goodbye.
Car tires are not "lower-spec" if they have the load rating.
I have only owned one cav with LT tires, and it's
also the only one with which I have handling
issues. I have always had car tires on my VW
vans; I have often had them fully-loaded or even
seriously overloaded and driven at speed on
twisty roads and up rocky 4WD tracks. Never once
had a tire-related problem of any kind with them.
--
Andrew Grebneff
Dunedin
New Zealand
Fossil preparator
<andrew.grebneff@stonebow.otago.ac.nz>
Seashell, Macintosh, VW/Toyota van nut
HUMANITY: THE ULTIMATE VON NEUMANN MACHINE
DEMOCRACY: RULE BY THE LOWEST COMMON DENOMINATOR
