2020s Aluminum Wheels and Large Rim Sizes

[bcroe]

Of late I am seeing a lot of cars equipped with aluminum rims
which require no wheel covers.  The rim is some 2 inches larger
than that of cars a while ago, for the same outer dia at the road. 
After some 90K on these, I have a few questions, and quite a
few complaints. 

I wonder if some expert will find serious flaws in my thoughts? 

For openers there are only a couple inches of rubber between
the rim and the road.  Are these supposed to HANDLE better? 
I see these as having much more chance of metal damage in
case of a severe road hazzard.  They are so low you cannot at
all see if they are under inflated, no wonder they come with
under inflation alarms.  These alarms require a reset process. 
More expense, complication, and failure modes. 

Experience to date is these tires are much more suseptable to
nails, and much more likely to be UNREPAIRABLE.  In the past
I have gotten around this by using an inner tube for the rest of
the tire tread life, but it appears that will not work here. 

Then we get to COST.  These wheels are not generic reusing
your original wheel cover.  You need all to be matching for that
specific car. 

Here cars are driven coast to coast, and not slowly, no time for
tire trouble.  So the spare is exactly the same as the ones on
the road.  AND after quite a few bad experiences with tire stores,
I will NOT let them TOUCH my cars.  I just drop off a wheel (no
appointment needed) for tire repair or replacement, pick it up
later.  To do even better, and to make wearout replacement
more convenient., I do 2 at a time, an axle.  So I have 2 spares
of each size, though in the past they might have been shared with
other cars equipped with a generic wheel.  They take more trunk
space. 

SO this vehicle requires me to BUY 2 extra aluminum wheels
just for it, and they COST DOUBLE what my generic wheels did. 
NOT ONLY THAT, the tires ALSO cost double what my generic
tires did.  I am very unhappy with being manipulated for my $. 

I recently checked out putting my previous generic wheels and
tires on the car, and THEY FIT PERFECTLY.  After all the
problems with tire failures and pressure checkers, I am getting
very close to just pulling the entire set off and installing my
excellant previous generation set, all 6!!  Bruce Roe

[TJ Hopland]

Rims and overall diameter started out fairly large then got small in the 50's?  Then in the 90's started getting bigger again for some reason.   I have no idea why anyone else know?

I think one reason they claim less sidewall is better is lower rolling resistance so better MPG.

Cars that would have had 13's back in my day now come with 18's as the base model size.  And on trucks and SUV's can you even get something smaller than a 20?  You wanna make a 3/4 ton truck ride worse?  Take away the sidewalls.

[The Tassie Devil(le)]

I find that one of the reasons for people going for larger sizes in rims, and lower profile in tyres is for aesthetic reasons.   Now they are making high-end rims with a whitewall painted onto the bead retainer which makes the low-profile tyre look like it is an actual White Wall tyre.

With modern cars, about the only thing one can do to make their cars "different" from all the rest is to change the wheels and tyres.   Virtually nothing else on the cars can be changed as all the fitted parts that are painted are structural pieces, or plastic coverings, and cannot be altered due to Federal Laws prohibiting alterations, as it interferes with all the safety regulations.

A lot of people just want to make their cars stand out, and others just don't care, as their car is just a means of transportation.

With the advent of good roads (less potholes) the need for taller sidewalls became a thing of the past, and the designers needed all the means they could muster up to meet the desired performance figures (Federally mandated).   Put a 2024 car on a 1924 road, and the car wouldn't last very long before it fell to pieces.   Those old cars had good suspension movement, and tyres were a part of that.   The large diameter wheels were there to make driving over potholes a lot easier than the smaller wheels of the '60's compact cars with their 13" wheels.

The advent of Aluminium Wheels was also about getting the weight of the car down.   Plus, no need for hub caps (another expense for the maker)

Lastly, Run-flat tyres are getting to be the norm so they makers don't have to put a spare tyre in the trunk.   Any method to cut down on overall weight.

Bruce.

PS.   When I look at buying a car, I now look at the wheels and especially the tyres, as if I cannot afford to replace the tyres, I cannot afford the car.  

[TJ Hopland]

I don't know how common run flat are but what does seem to be common at least on the newer cars I have been exposed to is a can of 'fix a flat' and a little air compressor you plug into the '12v power accessory port'.   

[smokuspollutus]

The larger rims facilitate:

-"Better" handling-no pesky sidewall to fold over

-"Road feel"-no pesky sidewall to cushion impacts or protect the hardware from shock, for the ultimate driving experience

-Larger brake hardware to comply with safety regulations of brake performance. Allows for the driver to devote his attention to the big screen TV mounted in the dash and still allow the electronic nanny time stop the vehicle just short of rear ending a school bus

-Bragging rights for having the largest rotating circular piece of metal amongst your friends

-Bragging rights for having the most expensive tires when it comes time to replace them from impact damage/improper inflation

-Corrosion from road salts, condensation from compressed air, and dissimilar metal corrosion at the hub keep the driver informed of when it is time to replace his vehicle, unlike old steelies that may allow the vehicle to be driven well past its "use by" date.

-Provides economic stimulus to the disadvantaged when leaving the vehicle unattended in urban areas via the removal of the rims from the vehicle and their subsequent sale on the black market

As proprietors of old iron, it can be difficult for us to be able to understand the many benefits and sophistication that larger rims bring to the motoring experience. I would recommend reading what the Experts™ in the automotive press have written about this subject over the past 25 years for further expansion of the points above.

[76Caddy]

Speaking of spares, our 2019 XT5 does not even have a spare tire or even a place to put one.  It has a "repair" kit in the cargo area in back.  Salesman said it was okay for fixing a puncture but if the sidewall was damaged, you're calling a tow truck.

Tim

[bcroe]

Thanks for all the input.  Here is some more of my perspective. 

I got out my super accurate propane recharging scale.  The doubly
expensive aluminum wheel with tire mounted weighed 48lb 4 oz. 
A steel wheel with tire mounted, actually intended for a slightly
heavier vehicle but physically interchangeable, weighed 40lb.  As
I suspected, the fancy aluminum wheel/tire was 20% heavier.

I suffered all drum brakes through the 60s.  The 11in disc brakes
on my big 70s car were the first I considered actually satisfactory. 
The 12in rotors on another car were even better.  These fit just fine
inside the 15in rims.  Only someone racing needs more than these. 
The fact that I could put my steel 15in rims on the newer car meant
they had not used any extra space for bigger brakes.  My old rotors
were vented, which I consider making then superior to the now
common unvented.  There is a problem after a couple dozen years,
that the vented rotors rust from the inside out, and can start
to fail before I wear them out (I hardly use the brakes, but they
had better work when I need them). 

The engineer here is not interested in making a car stand out. 
With all the exposure at the speed limit (at least!), I just
hope to slip through unnoticed.  The first time I saw such wheels,
I told the dealer they had a sign on them, STEAL ME!.  That
actually happened next door, to a couple  of the neighbors cars. 
More recently I saw them as a dealer TRIM PACKAGE OPOTION.  At
little cost to the dealer, every car on display had a very big
price bump.  I would have to order without it. 

For sure I have no patience for fixing tires or spares on one
of my leaps to a coast.  I am not allowed to use the words that
I feel for those repair kits or a mini spare.  I am also quite
dissapointed that the public just accepts such ........ without
complaint. 

Bstter handling, I expect such things on race cars.  Apparently
not so important to the public, as handling options were rarely
selected.  The stiffer springs, gas shocks, upgraded front and
sway bars, and tires inflated to the high end cover it for me. 

The effects of corrosion are yet to be determined.  I do know
that I have NEVER had to replace a wheel cover because of
corrosion, must be SS.  The steel wheels might need sand blasting
and repaint every 40 years here in the rust belt.  I eliminate
the damage to the lug nut etc surfaces when I do not let the
tire shop touch a car.  If the aluminum wheels develop corrosion,
it is just one more attempt by the mfrs to force us to get rid
of old cars and buy new ones.  Bruce Roe

[64\/54Cadillacking]

I've seen far too many late model newish cars locally getting flat tires on my local roads from all the potholes and horrible road conditions where I live. Unfortunately the reason behind the larger wheel, tiny tire sizes is strictly for aesthetic reasons, and maybe handling but not for a smoother ride that's for sure. I consider a low profile tire being a 55 series or under. The good ole 70 or 75 series was perfect for absorbing the largest of bumps, deep cracks in the asphalt and huge potholes.

Engineering wise, it's very difficult for auto makers to really make a car with low profile tires ride as smooth as our big Caddy's with donut size tires without reinforcing the body structure and or adding much larger body and control arm bushings for the car to be able to dampen the increase in road shock from the lack of beefy sidewall. Also modern tires simply don't ride as soft which also ruins the ride quality for many new vehicles.

It's no wonder I see so many people driving huge lifted pickup trucks with 35 inch series truck tires, or larger tires, including tons and tons of Jeep Wranglers with massive tires as well since they're the only vehicles on the road that can easily handle the serious punishment of driving on San Diego streets that look like bombs were dropped from the sky in a war zone on many of our streets and freeways that are not maintained AT ALL.

There's an app that residents can use to make a pothole report, and many people have post pictures of their wheels/tires being completely destroyed from driving over these massive potholes.

And yes, aluminum wheels don't help matters either, as they are far more prone to cracking. There was a local news report of an owner of a Tesla Model S that all 4 of his wheels got damaged including his tires from driving over a certain street that is well known to have multiple dangerously sized potholes that destroyed his wheels. He had to sue the city for the damages because the total cost to replace all 4 wheels and tires was around $4,000!!

My daily drivers is a Lexus LS460 with 55 series tires on 18 inch wheels. Originally the stock tire size is supposed to be a 50 series which is too thin IMO, so I installed a set of very nice slightly larger 55 series Continental Pro-Contact tires which really helped smooth out the ride in the car. But it's like nowadays you have to spend a lot of money for a high quality smooth riding tires with a short sidewall with low road noise as well.

I also own a 2005 Lexus LS430 with 17 inch wheels, which in IMO is one of the smoothest cars I've ever driven, yes, even when compared to my Cadillacs! Of course it doesn't ride as soft or even float down the rode, but what that car does so well is it absorbs road shock and vibrations even better than my 07 LS460 which is supposed to be the better car on paper, but it's not. The build quality is much better on these old LS430's, and suspension setup is beefier and simpler using much larger control arm bushings than what is in the LS460.

I miss the days of fat side wall tires, too many new cars I've driven lately, simply don't ride all that nice, especially where I live. Now maybe if you live in a city where your infrastructure is very well taken care of, and it's mostly smooth flat asphalt, then it might not be an issue, but driving on mostly concrete freeways, and extremely rough, broken, uneven asphalt that falling apart right before your eyes, then I say no way, get a truck or an SUV where you can install smaller wheels with larger tires will help one avoid the catastrophic affects of owning a modern sedan or crossover.