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pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

pende_tim

Premium Member

[Help] Ride Difference 20" vs 18" wheels

I am looking at a SUV that has as standard P245/60 R18 tires. There is an option ( for about $800 !!! ) to put P245/50 R20 tires on this SUV.

The problem is that 99% of the cars on the dealers lots have the 20" wheels, which I do not particularly want: not only the initial cost is high but the replacement cost of tires down the road is higher.

Having said that, what is the advantage of 20" wheels?
Do they ride better? Better traction? Better gas mileage?

With the R50 profile, would the ride be more bumpy since there is less rubber between the road and the rim compared to the R60 tire?

I am not looking to get them just because they "look pretty". Is there any practical reason for 20" wheels?
davidhoffman
Premium Member
join:2009-11-19
Warner Robins, GA

davidhoffman

Premium Member

Re: [Help] Ride Difference 20" vs 18" wheels

The R50 profile's shorter sidewall may reduce the response time for steering inputs and may reduce very slightly the reaction time for acceleration or braking. If the treadwidth, as you stated, is exactly the same, there might be a very slight decrease in fuel consumption for the R50s due to less internal tire friction. I doubt that it will compensate for the increased tire cost. Some disadvantages are that the ride is likely to be somewhat more rough due to the stiffer sidewall and there may be a higher probability of wheel rim damage due to curb impacts. Also there is the matter of the popularity of "dubs", which is one street slang term for wheels 20 inch diameter and larger. THEFT of those wheels and tires. Ask your insurance company about your intended vehicle's theft and vandalism claim history in regards to wheel sizes. You may be surprised to find out that some insurance companies will charge an increased amount if they break out their rates according to options on the vehicle.

If you are buying a true SUV that has 4 wheel drive for off road use, lower profile tires make no sense for driving on rutted, muddy, gravel strewn roads. If you look at true SUVs, they have relatively tall sidewalls for dealing with off road operations.

Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

Lurch77 to pende_tim

Premium Member

to pende_tim
On the average SUV, the difference in 18 and 20 inch wheels is mostly going to come down to what you think looks better and what you want to pay for. You're not going to notice much difference in the driving experience for the most part. Go for the 18s if they look good, and you'll save money up front and down the road, as you mentioned.

One positive for the 20s are they might help the vehicle sell faster if you ever do put it up for sale. People like big fancy wheels.

MooJohn
join:2005-12-18
Milledgeville, GA

MooJohn to pende_tim

Member

to pende_tim
The only reason for 20s over 18s is looks, period. The larger wheels are usually heavier and like you said, the shorter sidewall means a more harsh ride.

My brother's 4Runner came on 17s which were replaced with factory 20s. The ride is firmer but not much so, and he did it for the looks alone.
hosedagain3
join:2008-02-18
Canada

hosedagain3

Member

A chance of bent rims with the 20" from hitting pot holes.

BonezX
Basement Dweller
Premium Member
join:2004-04-13
Canada

BonezX

Premium Member

50 sidewall on 245's is still pretty big(12.2cm, 4.8in).

but anything over 18in on anything is kinda goofy, and realistically there is no performance gain from 20inch rims on an SUV.

aurgathor
join:2002-12-01
Lynnwood, WA

aurgathor to Lurch77

Member

to Lurch77
said by Lurch77:

One positive for the 20s are they might help the vehicle sell faster if you ever do put it up for sale. People like big fancy wheels.

*Some* people like big fancy wheels.

Beezel
join:2008-12-15
Las Vegas, NV

Beezel to Lurch77

Member

to Lurch77
said by Lurch77:

One positive for the 20s are they might help the vehicle sell faster if you ever do put it up for sale. People like big fancy wheels.

Until they realize how much the cost is to replace the 20's. I see rides here with 20+ rims running on bald tires.

Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

Lurch77 to aurgathor

Premium Member

to aurgathor
said by aurgathor:

said by Lurch77:

One positive for the 20s are they might help the vehicle sell faster if you ever do put it up for sale. People like big fancy wheels.

*Some* people like big fancy wheels.


You replied to a guy who owns 3 vehicles, the largest wheel among them being 16".

Hall
MVM
join:2000-04-28
Germantown, OH

Hall to pende_tim

MVM

to pende_tim

Re: [Help] Ride Difference 20" vs 18" wheels

said by pende_tim:

I am not looking to get them just because they "look pretty". Is there any practical reason for 20" wheels?

That's the only reason.... "looks"

For your (3) questions: The ride is likely to be less "soft" compared to 18" wheels due to the lower sidewall. On traction, they're both 245mm wide - height has NO factor in traction. I suppose the tires may be different, i.e. different tread patterns, but I'll go out on a limb and say that "traction" isn't a factor in the dealer opting for 20s vs 18s. Finally, on gas mileage, without breaking out a calculator*, 20s will rotate less times than 18s, but then you have to factor in the difference in profile (it could negate that) and the obvious one is the weight difference in 20" wheels/tires vs 18" wheels/tires.

* Just ran those two sizes through a tire calculator and other than sidewall height, almost 1", there's no meaningful difference (no change in gas mileage based on circumference alone plus the speedo should remain reasonably accurate).

BonezX
Basement Dweller
Premium Member
join:2004-04-13
Canada

BonezX

Premium Member

Re: [Help] Ride Difference 20" vs 18" wheels

actually you would lose a little bit of fuel economy on acceleration, due to the rotational mass being further out from the center of rotation, as well as potentially a slight loss in braking due to the higher forces required to counter the momentum. as well as the overall increase in mass of the rim depending on the design itself. it wouldn't be a terribly big amount, but it's still a loss.

Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

Lurch77

Premium Member

Good points. But that does depends on the material and design of the two wheels. When I had my old Tacoma, the 17" alloy wheels I put on it were significantly lighter than the 14" alloy wheels it came with.

Cho Baka
MVM
join:2000-11-23
there

Cho Baka to Lurch77

MVM

to Lurch77
lol, 15" here.

BonezX
Basement Dweller
Premium Member
join:2004-04-13
Canada

BonezX to Lurch77

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to Lurch77
is that with or without tires.

Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

Lurch77

Premium Member

With tires. The aftermarket wheels were a lightweight racing type wheel.

aurgathor
join:2002-12-01
Lynnwood, WA

aurgathor to Lurch77

Member

to Lurch77
I replied to a guy who wrote that: "People like big fancy wheels."
aurgathor

aurgathor to BonezX

Member

to BonezX
Actually, for a complete tire of same diameter and width, tires with a bigger aluminium wheel (and less rubber) are normally lighter. (this may not apply to steel wheels) But the difference between 18" and 20" will not be a whole lot.

BonezX
Basement Dweller
Premium Member
join:2004-04-13
Canada

BonezX

Premium Member

overall weight wise, its usually pretty close(unless your paying a fortune for forge alum), but a majority of the weight will be further out from the center of the rim.
davidhoffman
Premium Member
join:2009-11-19
Warner Robins, GA

davidhoffman to Beezel

Premium Member

to Beezel
I see a lot of aftermarket wheel upsizes with bald tires. It is somewhat irritating to know that the smaller diameter standard wheel with a better quality tire would have given them a much better long term value. The aftermarket wheel shops, and some of the discount automobile service places, love to sell huge diameter increases with very low quality tires. The guys and gals who purchased them liked the tires because the sidewall and the unidirectional tread pattern looked cool. They ignore, or do not understand, the significance of the treadwear rating below 200, the traction rating of B, and the temperature rating of C. Basically junk S speed rated tires.

Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium Member
join:2001-04-19
1970 442 W30

Doctor Olds to pende_tim

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to pende_tim
said by pende_tim:

I am not looking to get them just because they "look pretty". Is there any practical reason for 20" wheels?

There is no practical reason. In-fact you want to reduce unsprung weight, otherwise when you increase tire size the weight increases and that requires bigger brakes unless you don't mind hitting the brakes then waiting a while to stop. Plus it takes more torque to turn bigger tires/bigger wheels.

»www.caranddriver.com/fea ··· s-tested

Beezel
join:2008-12-15
Las Vegas, NV

1 edit

Beezel

Member

I had the option to go up to 21's on my Gen 5 Camaro. I just took the standard 18's. I will replace the factory wheels with American Racing Torq Thrust M, but I won't change size.

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

pende_tim to Doctor Olds

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to Doctor Olds
Thanks. I will look for a vehicle with 18" wheels. I am not a automobile "facionista" (spelling?) but want a good solid efficient yet comfortable ride.
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

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TheMG to pende_tim

Premium Member

to pende_tim
Less rubber (larger wheel) is less tolerant of potholes, rocks, curbs, etc.

I have 19" wheels on my car and have already bent a rim and burst a sidewall driving over a pothole. The sidewall got pinched between the rim and the pavement when the pothole was hit.

Smaller wheels with more rubber would be more forgiving.

There's also more road noise since there is less absorbing of vibrations.

More expensive wheels and tires.

IMHO, not worth it. Get the smaller wheels.

aurgathor
join:2002-12-01
Lynnwood, WA

aurgathor

Member

I was looking at cars couple of days ago (may need to buy one soon) and everything looked good on one, except it had 21" wheels. Car originally came with 16" wheels.

Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

Lurch77

Premium Member

Sometimes you can negotiate that. The dealer may be willing to swap wheels with another car on the lot, get some stock wheels from a scrap yard, or knock money off for you to buy new ones. Of course this is assuming it is from a dealer.
dbamber
join:2003-02-07
Bandon, OR

dbamber to pende_tim

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to pende_tim
Two differences that I can think of is the 20 inch rims, and tires will leave you with a lighter wallet, and a thicker payment book. If you like the looks, and don't mind paying more, go for it. Some vehicles out their have different size rims, and tires between the front, and rear, no problem until you want to rotate them. Some of the tire manufacturers give you only 1/2 the tread wear warranty in these situations. Along with wheel speed sensors this can be problematic. I know this firsthand on my E350 Sport. I wanted to lift the rear of the car up by going to a larger diameter tire. It worked really well until I got about 500 ft down the road and the difference between the front, and rear wheel speed sensors shut down all the safety functions ESP, ABS etc. Get what you wan't now, and don't make a major screwup like I did.