Anyone running 18" rims on M3 2014 2.0

[Avenida]

Just wondering what was your experience and if the driving experience, noise, fuel economy or changed dramatically.

Thanks

[staax]

Its the weight of the rim and tire that matters, not the size.

If you have a stock steel wheel with a 205/55R16 tire it'll weight about... 40 lbs or so?

If you happened to get a heavier 18" rim but a lower profile tire like a 215/40R18 the weight may identical and the whole diameter of the tire is hardly changed.

205/55R16 is 24.88" in overall diameter, 215/40R18 is 24.77 inches.

Almost identical.

Its all gonna depend on the weight differences between your stock tires.

[YepYep]

I am thinking that with such a big rim and very low profile tires, you dont have many choices but buying the high or ultra high proformance tires... And the 2.0 engine will be too weak to move the sticky tire. so you will at least to pay more on buying gas. I am using a DWS (ZR rating) on 16" size rim, and find that the prefect fit tire for the 2.0 should be only V or H rating tires...
I dont know the comfortable level of the low profile tires as mentioned... Maybe too hard for me... And may also shorten the suspension life...

[Aitch]

Stock suspension? You won't notice much of a harsher ride with the lower profile tires. But if you're not lowering it, 17s might look better. You can get non-ultra-high-performance tires in the right sizes though. And the stuff about the tires being too sticky for the engine to rotate or decreasing fuel mileage is bunk. Any mileage decrease would only come from heavier wheels and tires.

[Stathakos]

I lol'd at 2.0 engine not being able to move the sticky tire.

[fruitloops]

I lol'd at 2.0 engine not being able to move the sticky tire.
X2

[sarujo]

Different tires will have different rolling resistances. So to say that a tire does not affect fuel economy is bunk. But yes, you are right about the weights.



Stock suspension? You won't notice much of a harsher ride with the lower profile tires. But if you're not lowering it, 17s might look better. You can get non-ultra-high-performance tires in the right sizes though. And the stuff about the tires being too sticky for the engine to rotate or decreasing fuel mileage is bunk. Any mileage decrease would only come from heavier wheels and tires.

[Aitch]

Different tires will have different rolling resistances. So to say that a tire does not affect fuel economy is bunk. But yes, you are right about the weights.
Rolling resistance is different than implying a performance tire will be so sticky the car will struggle to move it.

[Stathakos]

^ it's all about dat unsprung weight. I can tell you from personal experience, (and so can fruitloops) mazdaspeed3 gen 1 wheels are heavy as shit and I noticed a big decrease in fuel economy. Also, when I had enkei's on last year which were much lighter I had decreased fuel economy compared to the 16 inch stocks but still better than the mazdaspeed wheels I have now

[fruitloops]

I just started tracking my mileage on fuelly after I got the rims. Didn't see a huge decrease. Can't break 500 kms on a tank 95% city driving though [emoji24]

[unknown]

Stock tire spec for the GT is 215/45R18 89W vs P205/60R16 91H for the non GT.
Since we're talking about the 2.0 engine not being able to turn those sticky tires, the GT has slightly larger front brakes, would they matter? (11.61-inch vented disc vs 11.02-inch vented disc front).

[gta_driver]

Stock tire spec for the GT is 215/45R18 89W vs P205/60R16 91H for the non GT.
Since we're talking about the 2.0 engine not being able to turn those sticky tires, the GT has slightly larger front brakes, would they matter? (11.61-inch vented disc vs 11.02-inch vented disc front).

How do you connect larger brakes with ability to spin the tires? Neither make sense.

First of all, the 2.0 will spin those tires, and second of all, the GT is a heavier car, and the larger brakes are supposed to compensate for that, plus add a small braking advantage since it is a GT after all.

You'll do better for braking with a set of sticky tires than bigger brakes in the case of Mazda3.

[The Wolf]

Its the weight of the rim and tire that matters, not the size.

If you have a stock steel wheel with a 205/55R16 tire it'll weight about... 40 lbs or so?

If you happened to get a heavier 18" rim but a lower profile tire like a 215/40R18 the weight may identical and the whole diameter of the tire is hardly changed.

205/55R16 is 24.88" in overall diameter, 215/40R18 is 24.77 inches.

Almost identical.

Its all gonna depend on the weight differences between your stock tires.
This is not exactly true. A 20kg 18" wheel and tire combo will "weigh more" than a 20kg 16" wheel and tire combo

[YepYep]

Maybe you guys used to drive ur car hard... But I can feel the difference that my engine need to run harder (just a little bit) especially when moving the car from still after changed a set of new DWS... And i got the prefect feeling of the new tires in the rainy days than good dry road surface...

[staax]

This is not exactly true. A 20kg 18" wheel and tire combo will "weigh more" than a 20kg 16" wheel and tire combo

Explain what you mean?

[The Wolf]

Explain what you mean?
The mass on an 18" wheel is further from the rotation point than in a 16" wheel. Think of it the same way as a figure skater doing a spin. Constant mass but they can speed up and slow down just by shifting mass further from their body.

[staax]

I think I understand what you're saying, but what the OP is afraid of is the weight difference between a stock 16" wheel and then an 18" alloy wheel. The difference would be marginal.

As long as he is keeping the overall diameter the same (ie: big rim, skinny tire vs. Little rim, fat tire) he will be fine for what hes concerned about.

[coppermica]

if you encounter a lot of potholes on your daily drive you may want to consider 17" . i see plenty of stories and pics of ppl on this site destroying a nice rim and tire combo on the lovely gta potholes .you will also have less road noise from a tire with a symmetrical tread pattern than a directional tread pattern on our mazda 3's. tirerack.com list a ton of helpful information on the tires they sell including noise, performance , quality , and customer feed back.

[The Wolf]

I think I understand what you're saying, but what the OP is afraid of is the weight difference between a stock 16" wheel and then an 18" alloy wheel. The difference would be marginal.

As long as he is keeping the overall diameter the same (ie: big rim, skinny tire vs. Little rim, fat tire) he will be fine for what hes concerned about.

unless you're buying very lightweight wheels, any 18" wheel weigh more than the stock 16" wheels. That combined with the centre of mass moving further away from the hub... it'll give a noticeable drop in fuel economy.

[jeffjones]

unless you're buying very lightweight wheels, any 18" wheel weigh more than the stock 16" wheels. That combined with the centre of mass moving further away from the hub... it'll give a noticeable drop in fuel economy.

Noticeable, very unlikely.
negligible, I would say so.....
I have used 16", 17" and 18" rims on my car and the best fuel economy were the 18's, next the 17's and last the 16's(Winters).
Again, lots of variables, but that is what has happened with mine.

[The Wolf]

I'm also speaking from experience. I noticed ~50-80km/tank less when I switched from my 16's to wide 17's.

You have to also factor in the fact that you will get worse fuel economy during the cold weather.

[jeffjones]

I'm also speaking from experience. I noticed ~50-80km/tank less when I switched from my 16's to wide 17's.

You have to also factor in the fact that you will get worse fuel economy during the cold weather.

I get about the same decrease from my 18's to 16's. Same ambient temperature. But the 16's are winter tires too.
I would say tire brand would make more of a difference then the 1" in size difference.....

Around the same ambient and driving conditions my averages are:
18's I get about 600kms/tank
17's I got about 575kms/tank
16's I got about 520kms/tank

I would blame 99% of the changes on the tread pattern of the tires.

I can't see a couple extra pounds causing a 10-15% decrease in gas mileage, If that was the case I would grab some carbon fibre wheels and get like a 50% increase in gas mileage.....

[The Wolf]

Like I've said a few times already, it's not the weight, it's where the weight is.

Oh well.

[Aitch]

Like I've said a few times already, it's not the weight, it's where the weight is.

Oh well.
WHAT? SPEAK UP, SONNY.

[KL3]

so to sum it up, I won't notice much of difference in gas mileage if I run gen2 speed3 rims on my gen2 skyactiv, but I should expect to see a decrease (if I notice)?

Will be riding at stock height

those GTA potholes ughhhhh....