Replacing Stock rims and tires

[abc123]

I am considering buying a 4.6 with a tech package. I see that the standard rimss are 18 x 7. Does anyone know what size is the maximum that you can put on a genesis? Can I use 20 x 8.5 or 20 x 10 all around. Or can the size be even bigger. Also, I am hearing about offset. What is that and what is the stock offset. Also has anyone changed their rims on the genesis yet ?

 

[emdoller]

Great question... I was going to write the same. I ordered my 4.6 and will get it in a few weeks. I was thinking 19 or 20's but also need to know the offset.

 

[musher51]

When I last looked up the Genesis at tirerack.com a couple of weeks ago, they listed 151 different wheels that fit, including a number of 19"s and 20"s.

 

[Bernie]

Here are pictures of a black Genesis (Korean) previously posted and photoshoped with various custom rims.

 

[GS300rich]

20s will definately fit. Just a matter of how wide the rear tires will be. The front tires are already 245, and it looks like the rear could hold a 10.5 or 11" rear wheel and a 285 or maybe even a bit bigger with the right offset. I would love to see a nice staggered setup with a meaty 285 rear tire

 

[Bernie]

The wheel requirements for the Genesis are 5x114.3 (4.5"), with an offset ranging from +35 to +45. On my Genesis, the original wheels are Dunlop SP 500 tires P235/50R18 with 18" rims. If you go to Tirerack.com and select Hyundai Genesis, and then select original equipment, the Dunlop tires specs indicate that the overall diameter is 27.1" (770 revs/mile).

If you wish to upsize to 19", you need to adjust the tire profile to a P245/40R19; this ensures that the overall wheel diameter (rim + tire) ends up being close to original rim/tire overall total diameter. As a result, your odometer precision ends up pretty well unchanged. With this rim/tire arrangement, the overall diameter ends up at 26.9" (774 revs/mile).

Likewise, if you wish to upsize to 20", you will need to adjust the tire profile to a 255/35ZR20. With this rim/tire arrangement, the overall diameter ends up at 27" (774 rev/mile).

Final note: if you go to Tirerack.com, you will notice that there are slight variations in tire sizes between manufacturers even if they share the same tire designation (e.g. Pxxx/xxRxx)

 

[VaiFan]

be forewarned, a 19-20" wheel will not only make the ride more harsh, but also due to the increased weight (unsprung weight) will tax your shocks and springs much more, thereby decreasing handling performance.
Yes, you get a bigger contact patch resulting in more grip, but it makes it much harder for the suspension to keep that heavier wheel smoothly intact with the pavement.
In other words, you are sacrificing actual performance and ride for "bling".

 

[Bernie]

Anyone interested in a tiresize calculator....

The calculator provides you with total wheel diameter dimensions (rim + tire) and allows you to make comparisons between stock wheels and alternates wheels.

http://www.miata.net/garage/tirecalc.html

 

[Bernie]

Here's an even better tire calculator from rims-n-tires

http://www.rims-n-tires.com/rt_specs.jsp

 

[Bernie]

Here's an even better tire calculator from rims-n-tires

http://www.rims-n-tires.com/rt_specs.jsp

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[Lord_Nikon]

Just remember about rotational mass and its effect on preformance and ride.

Oh ya here is another clean Hyundai with a decent wheel and tire setup
http://fatlace.com/hellaflush/?p=20

 

[GS300rich]

love the flush look in your link Lord Nikon, thanks for the links to the calculators bernie, I was looking for one of them. If I am not mistaken a 295-30-20 is the same height as the 255-35-20. I would love to see this on the rear of a genesis.

 

[GS300rich]

be forewarned, a 19-20" wheel will not only make the ride more harsh, but also due to the increased weight (unsprung weight) will tax your shocks and springs much more, thereby decreasing handling performance.
Yes, you get a bigger contact patch resulting in more grip, but it makes it much harder for the suspension to keep that heavier wheel smoothly intact with the pavement.
In other words, you are sacrificing actual performance and ride for "bling".

This is not completely true. If you have a forged wheel that is lightweight it will actually weigh less than the OEM. On my lexus my wheels are pounds lighter on each corner. If you use a chromed out bling bling wheel then yes you will have extra weight on each wheel and that will wreak havoc on your suspension and brakes and such. But a high quality lightweight wheel is the way to go when going larger than OEM.

 

[DieselHybrid]

Just think how much more rotational mass you would reduce by going to smaller diameter forged wheels!

As the old saying goes, "beauty is in the eye of the beholder."

When I see mega-sized wheels on a car I think, "Poor guy has no idea how those bling wheels are hurting his performance (acceleration, deceleration, fuel economy)- not to mention the added stresses on the vehicle's dynamic components."

My intention would be to buy the lightest forged 17" wheels that would fit the Genesis. Sure, it might not look as "bling" as other rides- but I'm more interested in function over something as fickle as "bling."

Freedom of choice also includes the freedom to be ignorant of the laws of Physics. But to each his own.

Peace.

 

[crepen]

Freedom of choice also includes the freedom to be ignorant of the laws of Physics. But to each his own.

Good thing you live in a free country

If it were that simple, F1 cars would ride on 115/95R12s or something ridiculous like that.

Note in the following I highlight CAN, since your mileage may vary based on car, quality of aftermarket parts chosen, and your personal preference as far as appearance, ride and performance characteristics.

Increasing tire width and decreasing sidewall height CAN bring tangible performance benefits as well.

In general, bigger wheels CAN provide better acceleration, decelleration and steady state handling, typically at the expense of top speed, handling on rough surfaces and "ride"

Mass is a significant input into the equation, but it is not the only one.

regards,
cmr

 

[Lord_Nikon]

Increasing tire width and decreasing sidewall height CAN bring tangible performance benefits as well.

To a point. but for the most part in the real world. all it does is make a car ride worse.

In general, bigger wheels CAN provide better acceleration, decelleration and steady state handling, typically at the expense of top speed, handling on rough surfaces and "ride"

Not really bigger wheels have greater mass which kill all preformance.
now if you said lighter wheel then you would be right.

Mass is a significant input into the equation, but it is not the only one.

regards,
cmr

Mass and tire compound make up 90% of it. That and tire contact patch and the driver.

 

[DieselHybrid]

@ Crepen-

"If it were that simple, F1 cars would ride on 115/95R12s or something ridiculous like that."

I think you would be surprised to learn that F1 cars don't use 22" wheels for the very reasons I outlined in my original post: acceleration, deceleration, cornering. F1 and Indy cars use smaller 15"-18" forged magnesium wheels that are just large enough to house carbon-ceramic disc brakes within their inner perimeter, with the rules size requirement being placed on the outside tire diameter. In the case of Indy cars that is 26"/27" f/r.

However, you're ignoring what matters most: the aspect ratio (length x width) of the tire's contact patch. A 17x9" (245/50/17) contact patch aspect ratio would be preferred over a 22x9" (235/30/22)- not just for performance but also for ride quality, comfort and rim security.

Also, when using oversized "bling" wheels, the smallest sidewalls (35-30 series) must be used in order to preserve nearly the same tire/wheel diameter as stock. As a result, the contact patch aspect ratio may actually suffer when compared to the stock wheel/tire combo.

So, you may think you "look" cool with "bling" wheels- but you just can't fool Physics; performance will suffer.

Peace.

 

[crepen]

DieselHybrid,

Your points are valid, and I actually had an indy tire as a coffee table at one point so I am aware of their dimensions (those suckers are heavier than they look). The point I was trying to make is that there is no absolute "small good/big bad" or vice versa - it is relative to the original configuration.

I find it hard to believe that car manufacturers continue to go to bigger and bigger wheels, particularly on high-performance cars, if smaller wheels was a simple solution. Porsche certainly knows more about this than you or I, and they don't use 15" wheels.

The "stock" setup of cars is designed by the manufacturer to achieve a certain balance of performance and ride. Aftermarket parts, including changing the tire size can alter that balance.

Factors such as wheel and tire manufacture/material, sidewall stiffness, tire pressure, temperature and, as you stated, most importantly the driver, have more weight overall than simple math regarding tire profile.

A 235mm wide tire on a 17" wheel *may* have a bigger contact patch, based on sidewall stiffness and tire pressure, it may not. Compound and tread design will tell whether that bigger patch does any goes, either sideways or straight ahead.

Lastly, whether it be engineering or market forces, try finding a 285mm wide 17" tire.

I agree fully that anyone throwing 45lb 20" wheels with budget tires on their car, hoping for performance improvements, is wasting their time, but carefully selecting high-quality components to match your desired vehicle performance is one way to personalize your vehicle.

Let's agree that "bling" is different than substance, but I won't be putting skinny 16" tires on my baby anytime soon.

 

[Flex59]

Lord Nikon: Thanks for the photos. Uhm! That is freaking sexy. I wish we could see the rims from the side!

Thanks,

Flex59

 

[Flex59]

Bernie: Thanks for the photos of the Genesis with different rims! It looks hot with practically everyone of them. I also own a Black/Saddel with Tech. Food for thought!

Flex59