Ride Quality and Wheel / Tire Size

[GreyZone]

What is the rule of thumb for how rim and tire size affect ride quality?

Whats the difference between an 18" rim and a 20" rim, if both have the same basic tire? Whats the difference between a 225/30 side wall versus 225/40 (as far as how it effects ride quality, I know ones taller).

Again, I am looking to smooth out the ride, not make it even more bouncy or stiff.

In an ideal world I could drop it an inch with SOFTER springs, and increase the rims to 19 or 20" and have a softer, smoother ride...but is that possible or am I just dreaming?
Modified by GreyZone at 1:27 AM 12/4/2007

[johnny_d]

18s will have a thicker sidewall than 20s. Thicker sidewalls means you'll have more air volume to bounce on, thus better ride quality. Dropping it will increase stiffness, so will increasing wheel size.

[rjdmmfl1]

Greyzone, a couple of things...

1. The first thing you want to do, if you change wheels, is try to keep the total tire diameter as close to factory as possible (26.3") ... for example factory specs is 215 / 55/ 17. This means, the tire is 215mm wide, the side wall is 55% of the width of the tire (215 x .55 = 11.825cm) ... 11.825cm / 2.54cm per inch = 4.655 inches for each side wall. 4.655 x 2 (two sidewalls)= 9.31 inches + 17 inches (size of wheel) is 26.31 inches.

I didn't mean to offend anyone with the equation, its just that many people don't fully understand what all those numbers are on the side of the tire.

Ok, now, for whatever size rim you get, you have to pick the appropriate size tire to fit the rim and try to stay as close to factory specs as possible. So for a 20" rim, you could get a 225, 235, 245, or 255 cm wide tire, however, note that when you go wider with the tire, the smaller the sidewall is gonna be in order to fit close to factory specs. And the smaller the sidewall, the more uncomfortable the ride will be.

So for 20" rims, here are some possible tires to stay close to factory specs

225/30/20 = 25.31225/35/20 = 26.2225/40/20 = 27.08

235/30/20 = 25.55235/35/20 = 26.47235/40/20 = 27.4

245/30/20 = 25.78245/35/20 = 26.75245/40/20 = 27.71

The ones in bold are the closest to factory specs. You can do the same equation above for 18 and 19" rims, ... in any case,some people wanted the lowest profile tires possible, meaning when the car moves, it looks like they are just riding on rims (probably feels like it also) But as Johnny stated, the thicker your sidewalls, the more comfortable your ride. So from the above tire choices, if I were to get 20" rims, I would probably go with the 245/35/20.. thus giving me very good grip on the road with the 245mm tires, but also decent side walls (3.37")

I hope this helps either you or anyone else choosing rims!

[GreyZone]

Thats real helpful rj, thanks. SO whats the best tire for 19s? I could do the math but thought maybe yo would know.

[generic808]

That all depends on how wide you go. I'll assume 8" because 19x8 and 19x8.5 are very common sizes. Anything wider and you might have clearance issues.

19x8:225/40/19 = 26.1"235/40/19 = 26.4"

19x8.5:235/40/19 = 26.4"

Your stock tire height is 26.3" so 235/40/19 would be your best bet if running 19's. rjdmmfl1 already listed the sizes for the 20's.

[Mr. Music]

Also, keep in mind the rubber compound. Some tires are harder than others; and the harder the tire, the harsher the ride and higher the noise. (I can't tell you how to figure out how hard the tire is though, I'd suggest asking somebody at your local tire shop or something...)

[GreyZone]

Okay, so with all that being said, the 19s are going to give a slightly better ride?

Also, what is the reason for staying "as close to manufacturer size" (26.3), is that becasue that will give the best ride? The max recommended I beleive is 27.1, but I am assuming that would mean shorter side wall and stifrer ride?

[Mr. Music]

Also, what is the reason for staying "as close to manufacturer size" (26.3), is that becasue that will give the best ride? The max recommended I beleive is 27.1, but I am assuming that would mean shorter side wall and stifrer ride?

Yes, a shorter sidewall will cause a stiffer ride, but having a larger or smaller tire diameter would mess up your speedometer, and you would have to have the cars computer recalibrated with the correct tire size so it would correctly display your speed.

[LongBeachCoupe]

Go with dubs! 19's will cost a lot more money in rubber.I got my 245/35/20 nitto extreme 555's for 120 delivered each.. DTD!

[rjdmmfl1]

"Go with dubs! 19's will cost a lot more money in rubber."

That's real talk! Greyzone, if you check, you'll find that because 19" rims are scarce compared to 20's and 18's, there aren't a lot of them made, thus there aren't alot of choices for 19" tires, thus they are more expensive. You will have a harder time finding tires for 19" rims, but if you are dead set on 19's, I think it is the perfect look for our car, and you can go with 235/40/19 as Eric stated above. Having 235/40 profile tires and a 19" rim is almost perfect for factory specs and will gove you an even nicer ride (all things considered) than 35 profile tires!

[LongBeachCoupe]

I agree except the phrase"and will give you an even nicer ride" It may feel better on your arse... but it dont look better!Hows ya like dat fo grammar!

[generic808]

18's all the way! I feel they are the best size for the Altima's. They are a good balance between looks, ride quality, and price. 18x8 on 235/45/18 will get you to EXACT factory specs (26.3"), but 225/45/18 (26.0") will be the easiest and cheapest route to go. There's a million tires at that size and they're priced just right. You can find cheapy tires for $100 and they can range up to the $200 mark. But, the $130 Falken FK452's will be the way to go.

Riding on a 235/45/18 will be a lot smoother than on 20's, that's fo'sho BTW my wheels are 18x8 on 225/45/18 so you can get an idea of what it'll look like. Good luck with your decision!

[Loop]

Nice wheels

[GreyZone]

This is great feedback, you guys are really helping me to learn this stuff. THanks!

[stereoca]

I'm also looking for 19" rims. Thinking about getting 8.5" width with 245/40/19 rubber. Can someone tell me what offset I should be using and whether there will be problems with clearance? I want to get the widest tires possible without clearance problems.

Thanks

[johnny_d]

Offsets between 35-45mm, 20x8.5 should clear

[generic808]

+35 should clear, but I've always recommended a +38 to +45 just in case you decide to drop. At +35 8.5" wide, you may or may not rub.

[LongBeachCoupe]

20x8.5 38 offset over here.... Whats the obsession with 19" wheels guys? I dont understand... Get more wheel for less money!

[GreyZone]

from purely an appearance standpoint, I like the look of 20s the best.

Another issue I've run into is road noise. So what's the general rule on road nosie with tires? I'm assuming the wider the tire and softer the rubber the louder the noise?

[LongBeachCoupe]

I dont know the specifics, but my tires are soft and big... and it does make significantly more noise than stock... its only really noticable when you have the windows down on certain pavement (on the hwy by me theres patches where they re-do the area bc of potholes n crap... they do it with like a sidewalk material, which makes more noise)...

All in all, its not that bad, but you will have issues using the bluetooth with the windows down, going 75.... other than that... its all good

[GreyZone]

What difference did you notice in ride and handeling? (your wheels look great)

[windex]

Whats the obsession with 19" wheels guys?

Personally, I dont like 20's too big and too much show. Since I plan on boosting I'd want lighter rims and 20's would be counter productive to this.

[johnny_d]

Hey Eric, I still haven't gotten my wheels yet because of the offset issues, I wanted a 2'' lip but it seemed that the only ones with that feature that I like are the Sportmax 502s. It is a 2-piece construction. Now I hear a lot of ppl liked them, but alot more ppl hate them. Now I don't know what to choose anymore. Some of the ones I like, for example the Tenzos GF7, with 43mm offset, you lost all the deep dish look already. I dont want to put 18'' wheels coz i put them on for looks, not for performance so going up 1/2'' in radius defeats the purpose SO yea, i'm still looking and looking. And no, I won't put out more than 2K for wheels and tires. Any remedy?

[generic808]

You could always put a car on bricks for a free set of wheels Just kidding! Please, don't do anything like that!

I'm personally not a fan of deep dish wheels so I don't think I'd be of much help in that department. I just think they're a little overdone and played out, especially in the last couple of years. I like the more race/mesh type look for my car; hence, my choice of wheels.

Have you ever thought about the G35 Ray's Engineering 19's? I think those wheels are hot! I'm debating whether or not to buy a set so I can swap them out depending on my mood.

I do think these Racing Hart J5's look hot.

Of course the G35's look better though

[johnny_d]

I like those Racing Harts J5 too, of course on a FWD offset it won't be that deep unless I have a wide bodykit hmm, they're about 2000 for a set huh? let me look more closely

[LongBeachCoupe]

Ride wasn't affected really... i was very surprised... What i did realize is the impact on acceleration, and on my nerves when im parallel parking... And i must say that i dont agree with the guys who say its "too big" or complain about the impact on the speed of the car... mine are heavy because i got them cheap... you can get lightweight wheels... But what you dont get with 18"s is the looks, and the questions.... They put 18"s on lots of stock cars now, so its not that big of a change... Ive been asked numerous times "damn how big are those bad boys"... and "i like what youve done with it"... If i had 18"s with led lights built into them that danced to the trans-siberian orchestra i dont think 18"s get the same looks

[GreyZone]

If i had 18"s with led lights built into them that danced to the trans-siberian orchestra i dont think 18"s get the same looks

hahahaha, got the visual...yeah, that's part of what I want also...NOT to look stock (although generics 18s look great and definitely non-stock). THe 18's though would look much better without the wheel well gap, hence all our discussions on droping the car). I like the way BMWs etc look with wheel well gap, its nonexistent. Why couldnt they have done a better job with that stock? Oh well, love love love the car...just needs a few mods.

[dlee360]

Hey Guys!Does anybody have a problem with putting 18s (235/50/18) on their altima? My tires rub on the side wall when I have any weight in the back seat and bugs the heck out of me. I also got the rims and tires at discount tire, shouldn't they have known that this may be an issue?

Thanks guys!D

[GreyZone]

50s seem a bit tall...when did you get them? Discount is great about swapping things out (at theri cost) when things dont work out....and yeah, IMO they should know thats a potential problem.

One thing to check that could help you out: Docount Tire has specs that says the total diameter size should be NO BIGGER THAN 27.1" I would be curios what your total diameter size is (guys on this site can tell us). If it's over 27.1, according to their own information, they will have to replace it for you with a shorter side wall.

[generic808]

Hey Guys!Does anybody have a problem with putting 18s (235/50/18) on their altima? My tires rub on the side wall when I have any weight in the back seat and bugs the heck out of me. I also got the rims and tires at discount tire, shouldn't they have known that this may be an issue?

Thanks guys!D

How wide are your 18's? 235/50/18 is a little too tall, but if you're only 8" wide, I wouldn't think that they would rub. What offset and how wide are you? I'm assuming you have a wrong offset, that's why you're getting the rubs.

I'm on 18x8, and a 235/45/18 would be the ideal fit. I'm on 225/45/18 though.