Sales Are Way Off, Could It Be the Tires?

This new fad of larger wheels and how-low-can-we-go tires just might be
scaring off the middle-aged bread and butter customers.

Not too long ago, -75 and -80 tires were the norm. Wheels were mostly 14
inch for typical family cars and station wagons. Those sizes and profiles
must have evolved by the application of good engineering sense. They
delivered fine performance and durability.

What's driving the recent trend? Today's cars look like they're riding on
their rims. Could it be this is a cheap and dirty way to lower the cars?
Intuitively, they look like a hard ride and easily subject to impact damage
from road hazzards. Also, being as wide as they are, it would seem
difficult to get them to wear evenly across the tread and equally difficult
to achieve alignment angles which are always calculated to the center of
the wheel. Is there a bonafide reason to these new designs, or is it just
stylists' whim?

A popular theory is these low and wide tires provide better cornering and
traction. Is that really the case or just advertising hype? How about
hydroplaning? If wide tires hydroplane earlier, then there is no merit in
the traction claim. As for cornering in a passenger car, its hard to beat
a VW Scirocco and those typically were equipped with -80s.

Frankly, oversize wheels and undersized tires turn me off esthetically.
Eyeball engineering tells me they are all wrong. My guess is a sizeable
minority feels the same and are avoiding the new models solely for that
reason.

Manufacturers need to offer reasonable tire options. Particularly, the 14
or 15 inch wheel with -80 profiles. Keep in mind there are buyers out
there who remember 6.70-15 wheels and tires and that roughly corresponds to
-90 profiles.

 

Will these rim and tire combinations accept snow chains ?

Bill

 

A few comments:
(1) Low profile does not automatically (and very seldom does it) mean a
wider tread. Besides, tire manufacturers finally learned that they can
design sipes and wide circumferential grooves in the treads to solve the
hydroplaning issue. For some reason, they were pretty stupid about the
obvious for many years. Nowadays (is that a word?) wider does not mean
inherently susceptible to hydroplaning with half-way intelligent tread
design.
(2) One advantage of larger wheels and lower profile tires is that for a
given tire OD, the brake rotors can be larger - that may be one of the
main drivers to the larger wheels, as attaining problem-free brakes
seems to be a problem on many (most?) cars these days. One of the first
mods I did to my Concorde was to go from 15 to 16" wheels so that I
could convert it to the larger factory rotors - the LH cars really need
those.
(3) One of the biggest downsides of larger wheels is that the rotational
moment of inertia is greater, so straight line acceleration suffers.
(4) Another downside of larger wheels is that tires are priced like
bikinis: As the amount of material in them decreases, the price increase
exponentially (compare prices of 15, 16, 17, 18, 19 inch tires and you
will see what I mean).
(5) As far as the harder ride with lower profile: That can be partially
compensated for with suspension and spring design, although unsprung
weight cannot be compensated for no matter what - and that contributes
to harsher ride.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

No offence, but I do not like the image of my Bonnie with 14 inch -80's
tires.

 

I have 70 on my Concord, I believe my wife has 65 on her Sybring.
I feel the 70s are the best compromise.
My cousin has a Volvo with very low profile tires. The only difference
I've noticed is a harsh ride on breaks in the pavement.

Yes extremely low profile on street cars is just styling IMO.

+Better cornering, more positive steering, looks to some.
-Worse for hydroplaning all things being equal, harsher ride, more tires
and rims damaged from potholes.
It has been mentioned that hydroplaning can be made to equal a regular
tire, but I disagree on the conditions I sometimes experience. Like
going up a steep mountain road in heavy rain with a stream of water
coming down in the depressed from traffic roadway- just like driving
up hill on slick ice. I found a 70 tire that will handle this, but
noticed some all season treads from the same manufacturer that obviously
wouldn't.
-They require much more spare wheel well height, so many cars have a
much narrower spare and can't take the flat tire in in the spare well.

They are extreme styling. Many vehicle models are still available with
65+.
The silliest thing I saw was a large truck based SUV (Yukon or similar)
with extremely low profile tires; 45 I believe. That vehicle would tip
over before the cornering of those tires was effective.
Just kiddy stuff, like those trunk fins that are useless at legal
speeds.

You are going too far back with 75+ profile.

 

IMHO it takes about a 60 series tire to get a good compromise between
ride and handling. However I do see your point, there's a lot of
vehicles out there with much lower profile tires than even that...

nate

 

i couldn't agree with you more!!the"play' of all companys just not
tires is to the absurd and over hyped sell on the ignorance and
strupidity of the consumer!!greed is as greed does!!but the tire thing
is mostly a warm and freindly client type of situation.but stupid is as
stupid does makes this an epidemic of national lunacy!!and i thought
the NRA was nuts!!

 

Why is everyone insisting on keeping "everything else equal"? There is
nothing - absolutely nothing - inherently more hydroplane-susceptible
about low profile per-se if the tire is sized properly with the lower
profile. I'm not into the extreme either (I have 60's on my Concorde,
and that is "extreme" as I want to go), but when one goes to a different
size (larger wheel & lower profile), one simply specs the numbers to
maintain the same tread width ( => hydroplaning susceptibility) and
tread OD (speedometer/odometer reading).

You could go to smaller OD and *still* maintain the same tread width
(hydroplaning resistance) if you wanted to. There's no reason one
couldn't go with larger wheel, lower profile, *and* narrower tread if
hydroplaning is the concern while maintaining speedo accuracy -
absolutely no reason.

It's ridiculous to list worse hydroplaning as an inherent property of
lower profile - because there's no reason to keep "everything else
equal" - the conversion charts reflect that.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

If you think a org. that is for common sence education and fights for a
constitutional guaranted right is nuts, then your other conclusions are
probably pathetly off base also. KB

 

Well if it is for common "sence" education.... you failed.

 

If your strongest rebutel is my spelling, which on a newsgroup I am not
that worried about, then you have no argument. KB

 

That would be "rebuttal". ;-)

 

Ya beat me!!

 

No, it wasn't. But it was all it deserved. As a NRA member, I found your two
post's were sorta self defeating.

 

That'll be "...an NRA..."


DAS[/QUOTE]
No, it wasn't. But it was all it deserved. As a NRA member, I found your
two post's were sorta self defeating.[/QUOTE]

 

Before you have a rebuttal, wouldn't you first have to have a buttal?

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

No, thank you, but it sounds too kinky for me.

Dave

 

I think it would have to be called a butt, minus the al before you can
decide to rebutt al. Like he said, this is usenet and doesn't count
as a real life experiment.

...Ron

 

No, it wasn't. But it was all it deserved. As a NRA member, I found your
two post's were sorta self defeating.[/QUOTE][/QUOTE]

Not to mention "post's" is neither a contraction nor
a possessive case noun, and the phrase is "sort of".

 

While I agree that often the lower wider business is taken too far, I
don't think we will see any return to -80 profiles on automobiles.

The tire companies love 'em because for some reason people are willing
to pay more for low profiles. I bet that the automakers are not paying
these premiums, but that only the aftermarket buyer does.

John