There are a lot of questions posted about which size to use, and how wide of a wheel to use, especially when plus-sizing on the US-spec 6. So, here is an easy guide to refer to when looking for replacement tires. First, let's breakdown what the size numbers/letters mean:

P215/50R17 93V

P = Passenger Tire (does not appear always)
215 = Section width (in millimeters)
50 = Section height or aspect ratio (ie. sidewall is 50% of section width)
R = Radial construction
17 = Rim diameter (in inches)
93 = Load Index
V = Speed symbol

All of the components of your tire size are important, but when choosing a replacement or plus size, many of those numbers will change. You may have a wider tire with lower aspect ratio and a larger wheel. However, the last two characters are the most important.

For the US-spec model, you MUST choose a tire with at least a 91 (or greater) load index and a speed symbol of H or greater (H, V, Z, W, Y) [NOTE: Winter tires are excepted from this stipulation]. These last two characters refer to the internal construction of the tire and it is important to maintain the same or greater load and speed capability of your tires as per Mazda's recommendation.

What follows is a guide, by rim diameter of the acceptable replacement sizes for your 6, which rim widths are acceptable for that size and the minimum inflation pressure for that size on your 6. Please refer to this guide before posting questions about what will work on your 6 (for simplicity, I am excluding the P designation and the load index/speed symbol, see above for requirements). This list has been thoroughly researched. If you don't see a size listed here (ie 215/45R17), then it is not recommended for the US-spec 6.

16" (original equipment wheel is 16x7)

205/60R16 5.5"-7.5" 32 psi *original equipment size*
215/55R16 6.0"-7.5" 33 psi
215/60R16 6.0"-7.5" 32 psi
225/55R16 6.0"-8.0" 32 psi
235/50R16 6.5"-8.5" 32 psi

17" (original equipment wheel is 17x7)

215/50R17 6.0"-7.5" 32 psi (93+ load index), 33 psi (91 load index) *original equipment size*
225/45R17 7.0"-8.5" 35 psi
225/50R17 6.0"-8.0" 32 psi
235/45R17 7.5"-9.0" 32 psi
245/45R17 7.5"-9.0" 32 psi

18" (original equipment wheel is 18x7)

215/45R18 7.0"-8.0" 35 psi (6s, 6i), 38 psi (Mazdaspeed6) *original equipment size*
225/40R18 7.5"-9.0" 38 psi
225/45R18 7.0"-8.5" 38 psi
235/40R18 8.0"-9.5" 38 psi
245/40R18 8.0"-9.5" 38 psi

19"

225/40R19 7.5"-9.0" 36 psi
235/35R19 8.0"-9.5" 39 psi
245/35R19 8.0"-9.5" 36 psi

20"

225/35R20 7.5"-9.0" 40 psi NOTE: This fitment is BORDERLINE, but acceptable. Make certain you are choosing a reinforced tire (LOAD RATING 90).

NOTE: Section widths of 235 and above will probably require fender rolling. Check the offset of your wheels carefully before purchasing replacement tires. I was going to also include the overall diameter for each tire, but this can vary from manufacturer to manufacturer by .1-.2". Suffice to say that these tires fall within the "-2%, +3%" rule, meaning they are not more than 2% smaller or 3% larger than the original equipment tires, which have an overall diameter of 25.5 inches.

TAKE NOTE: When selecting replacement wheels and tires, the relationship of the wheel width to tire section width is very important! For maximum handling benefit, mount the tire on the widest wheel that size will allow. Mounting a tire on the narrowest width allowed will give better ride comfort, but won't give the best handling. In many cases, handling may be worse than before by mounting a wider tire on a narrow rim (ie. 235/40R18 on an 8 inch wide wheel vs. 215/45R18 on an 8 inch). Installing wider tires on your 6 will likely yield a handling improvement only if you have a wheel wide enough to take advantage of the extra tire width.

Awesome man, this should be pinned asap!

Great write up toyoguy! Thank you.

Question (235/50R16 6.5-8.5" 32 psi). Does this mean that the stock 16x7 can run 235/50R16?

Nice list.

Chop half of those sizes off the list because they won't fit regardless of whether the fenders are rolled. Anything even a little bit larger than (or in wider cases, equal to) the stock diameter will be a problem behind the rear door unless you run a very skinny tire. Just a very minor reduction in tire diameter solves this. Thankfully, ToyoGuy's general guideline of not reducing your tire diameter by more than 2% doesn't seem to affect the Mazda6 (or at least I haven't seen any evidence of it).

245's will fit if you have the right offset wheel and you get the proper diameter (limited essentially to 245/45/16 or 245/40/17), yet 235/45/17 has been confirmed to rub both in front and rear. 225/45/18 also seems to not fit in the rear (according to a recent thread), though 225/40/18 fits rather easily. Those examples are all on +48mm offset wheels, an otherwise very usable offset. I'm sure there are many other sizes on the 'omit' list too.

With your fenders rolled as much as possible, you MIGHT get the following combinations to work:
a 225 wide tire on a +40 wheel.
a 235 wide tire on a +45 wheel.
a 245 wide tire on a +50 wheel.

To be safe, I'd recommend you take that down a step, in other words don't exceed a 225 on a +45 wheel, a 235 on a +50 wheel, etc. Some tires are wider than others and there is no way to predict what you are getting. You probably wouldn't notice much of a difference with a tire width change of only 10mm, so concentrate instead on getting a nice, reputable make/model of tire. A slightly reduced tire diameter helps fitment slightly by providing more camber gain by the time the suspension compresses, but ToyoGuy advises not to reduce your diameter by more than 2%.

Lighter is better except for in strength- lightweight cast wheels should be coupled with taller profile tires unless you drive on smooth streets. Wider wheels make the most of your tires- try to get a wheel wider than your tread width. I'd recommend a minimum wheel width of 7.5" (though 7" wheels are technically "safe") for most sizes with 8" highly preferred.

If you're not going to roll your fenders, you can do no better than a 225mm wide tire on the stock wheels are a 215mm wide tire on a +50mm aftermarket wheel. Most aftermarket wheels have a lower offset than 50mm, thus rolling your fender is required for almost anything aftermarket.

Remember, higher tire pressures (per ToyoGuy's list) mean you are putting less rubber on the ground, getting a firmer ride, and possibly (though unlikely) setting yourself up for uneven tire wear. A firmer ride (be it from aggressive performance tires, low-profile tires, or high tire pressures) seems to drastically reduce shock life. Tires are THE MOST IMPORTANT PART OF THE CAR and you should carefully consider your choice to match it to your suspension and goals.

Finally, lowering springs do NOT cause (or even influence) whether a tire setup will rub. It only increases the frequency and/or severity of the occurance.

While I appreciate your comments, stretch, this thread is going to get complicated and confusing very quickly (exactly OPPOSITE the point of this thread). This is meant to be a simple, easy to understand guide about what sizes are acceptable, what width wheels they require and minimum air pressures.

These are oft-asked questions and this is meant to be an easy reference before posting another thread about, "What air pressure do I need?" or "Will this work on an 8-inch wheel?" There's too many of those already. For the sake of simplicity, save the offsets, what combos might/might not work if the sun is pointing in the right direction, etc. conditions for another thread.

Also, note: there is no guarantee that the 245 widths will fit (again, serious modifications may be necessary) but the tires listed meet the criteria for acceptable replacement and plus sizing.

It's not like anyone listens to me anyway. I hope I didn't complicate things too much, but I think that's the nature of the beast. A lot of the tire sizes in your list will not fit (though they're technically safe). I'm the over-complicated disclaimer.

In summary: when in doubt, panic.

Just in case it reads that way, I wasn't being sarcastic when I said, "Nice list."

Okay, now you're being humble? I'm sure a lot of folks on this board respect what you post (myself included) due to the amount of trial and error you have employed on your own 6.



I appreciate the clarification!

What is the width and offset of the stock 17" wheels?

7" width. +60 offset.

EDIT: its right there in the wheel and tire faq btw
http://forum.mazda6club.com/index.php?showtopic=21280

I HAVE AN IMPORTANT QUESTION IF ANYONE CAN ANSWER FOR ME!!
I WANT TO BUY THEM 19" BBS RIMS.THE HAVE A 2" CHROME LIP IN THE FRONT AND 3 " LIP ON THE BACK.THEY ARE BEAUTIFUL RIMS.THE GUY SAID HE CAN GET THE RIMS I WANT WITH A BOLT PATTERN OF 114X 5 FOR MY CAR.EVERYTHING FITS PERFECT EXCEPT IT HAS A 38MM OFFSET.WILL THOSE FIT MY CAR.THE MAZDA6 5- SEDAN V6???
WHAT SIZE TIRES WOULD I NEED FOR THOSE RIMS?

See above for tire sizes that work in 19". I'm no expert on wheels and offsets and such, but everything that has been posted so far in the wheels/tires forum would seem to indicate that a +38 offset will have big problems with rubbing even with fenders rolled. You'd need like a +48.

Vendors must be board sponsors in order to solicit sales on car parts on this forum.

I stand by my earlier statement that 20 inch tires are NOT RECOMMENDED for the 6. There is no tire on the market with sufficient load rating for the 6 in 20 inch.

Steve, I'm only doing this in the interest of keeping this open. I gotta eliminate the flames and the fire-starter posts!

Mods, perhaps it's time to put a on this one? Lest we get any more "contributions" from bling hawkers.

Nope, I will not lock, but I will edit the hell out of it!

Thanks guys! Sorry about that post i didn't know the terms.
And yes there is a tire out that can carry the load, check out the Nitto NeoGen's.
Go ahead i know your a little curious.

http://pg.photos.yahoo.com/ph/alkeez01/det...7.jpg&.src=mail

From Nitto's own website:

225/30ZR20 85W Overall diameter: 25.35 inches

This tire is the right height, but with a load index of only 85, how can you say that this tire has enough load capacity? For the umpteenth time, the Mazda6 REQUIRES A 91 LOAD INDEX MINIMUM! (Damn, I just burst a blood vessel!)

But hey, what do I know? Obviously nothing.

I think the tire he is using is the Neo Gen 225/35R-20. The 225/30R-20 is suggested to mount on a wheel with a minimum width of 8 inches; those wheels are 7.5 inches. The 225/35R-20 has a load index of 90, still not good enough but at least it's close. I would still recommend staying away from 20's unless they are for show purposes only and they will not be driven on. From looking at those pictures you mean to tell me that your wheels will survive even the smallest of pot-holes, I think not.

225/35R20 is 26.42 inches tall, nearly an inch taller than the stock size and beyond the 3% rule. This is not acceptable (plus, as you said, is only 90 load index). I stand by my earlier statement that there is no acceptable 20 inch tire on the market for the 6. If someone can prove me wrong, I welcome the reply!

Remember Toyoguy, it's ALL about the LOOK!!

Safety, handling, noise, traction, durabilty, speedometer/odometer accuracy... F*ck all that!

Word!

Can anyone tell me i can mount a 17' wheel with an ET of 35 - the offset - with a 215/45/17 tire or 225/45/17 tire. Thanks.
Does anyone knows or has on the m6 the TSW RIB wheels??

I'd hazard a guess that an 35 offset is just too low for the 6, even with 17's.

I don't suppose 245/45/16's on a 50mm+offset Rx7FD wheel will give me any problems? Or will i need to roll my fenders?

That's too small of a tire. 245/50R16 would be better, as long as the wheel is at least 7 inches wide. But it's probably going to rub on either the fender or suspension.

I have 225/45/18's on my wagom with ASA's AR-1's wheels 52mm offset, no rubbing at all!

quik question, do you think i would have to roll my fenders rx8 16's and tires with 235 width? same question for 225 width

ok no one answered my last question thats kool here's another, can the stock lug fit with rx-8 16's? please answer

Are you lowered? What type of tyres (R-comp/street?)? Regardless, I'm not 100% sure, but I believe you will rub if you're lowered, and most more than likely not if you're not lowered - although it will look kind of funny... (Big car, tiny rims, huge fender gap).



Yes, the stock lugs will fit.

thanks banghatch for the reply, i'm not lowered yet but i think i'll go with 225's in front instead. i plan on lowering the car in a couple of months, plus i plan on staggering the tire's 225 in front 215 in the rear. in theory it should help undo some of the understeer

I have a question. I am going after market wheels and tires now.... I have chosen my wheel, Kazera KZ-V, offset +50, but I havent chosen the size. It comes in 17x7 and 18x7......

If I ran 17x7 with a 225/45/17 tire, then my tire would be roughly .5 inches smaller in diameter than my stock tires (215/50/17 on a 17x7 rim). This would result in a 1/4 inch larger wheel gap, correct?

If I ran 18x7, should I use a 225/45/18 or 225/40/18? I have seen guys on here running both sizes. The 225/45/18 puts me .4 inches larger diameter than stock and would therefore result in the wheel gap lowering .2 inches?

The 225/40/18 would put me .4 inches smaller than stock and would result in a wheel gap of .2 inches greater? Also, because its a 7 inch rim, I would get more of a bulge with the 225/40..... so Im assuming that is one of the reasons why you reccomend a wider rim with the 225/40 tire.

Therefore, what would be "better" in terms of mounting the proper size tire on the proper size rim, having the least sidewall bluge, and not changing the wheel gap as much, a 225/45/17 or a 225/45/18?

I have been leaning towards the 225/45/18s.....

Correct.



Correct regarding the wheel gap, but if you go 18x7 then you have to use 225/45R18. 225/40R18 requires at least a 7.5 inch wide wheel.



In these low profile sizes, you have very little sidewall bulge to begin with, but the 18 will have less bulge because it is a shorter sidewall. The 17 will have a slightly larger wheel gap and the 18 will have a slightly smaller gap, but it will be difficult for you to notice this to the casual eye. Is this appearance your only criteria for choosing 17 vs. 18? There are a lot more important performance characteristics to consider when choosing a size...

interesting.

im running 225/55 on my 16x7 stockies at the moment. im looking to get either the FD3S RX7 (16x8) wheels or the RX8 16s (16x7.5)

are the 16x7.5 wheels the sweet spot for performance/comfort? i dont want to lose too much sidewall by going to 16x8...

You're not going to lose any sidewall by going to a wider wheel. Since the 225/55R16 can fit on a 6.0-8.0 inch wheel, the 7.0 is going to give you the middle ground between ride comfort and handling. The 7.5 will decrease ride comfort slightly and increase handling slightly.

There are a handful of things I am considering, but I wanted to clear up what I speculated on the fender gap. I wanted to go to a lighter weight wheel and run a 225 series tire. The 17x7's weigh 17.2 lbs and the 18x7's weigh 18.5 lbs, so both are a good weight loss compared to stock.

I wanted a wider tire than stock, so Im going 225. I wasnt planning on rolling the fenders, so I tried to get a wheel with the offset around 50 and I wanted a lighter weight rim and I liked the look of the KZ-V's so it was a perfect match. Plus, they dont cost an arm and a leg.

I plan on using an all season tire, so its either going to be the Toyo Proxes4, Avon Tech M55 A/S, or Continental Contiextreme Contacts. All are within 20 bucks each of each other but im leaning towards the Proxes or Techs...

I cant decide between the 17x7s or the 18x7s........ im slightly leaning towards the 17s because even though they increase the fender gap slightly and would have more of a sidewall bulge, the tires alone would be 100 bucks cheaper for the set and the rims would be 100 bucks cheaper for the set and the 17 combo would weigh much less.

I would like to use the current 235/40/18 tires that I have sitting around the house. I noticed that in the first post that i should use an 8 inch wide wheel. Is there any way a 7.5 inch wide wheel would work? I like the Koseis and they are 7.5 inches wide (reason for asking). Thanks in advance.

Let's put it this way. Sure, you could squeeze that tire onto a 7.5 inch wheel, but the result is the tire will not be positioned at a proper angle. Therefore, the area just above the bead (on the sidewalls) will crack (due to excessive stess in that area), and the center of the tire will wear out very quickly due to the increased pressure in the center of the contact patch. So, the short answer is no, it's not recommended.

Negatory. You need to find a 18x8 wheel to put them on.

Thanks. Not what I wanted to hear, but what I needed to hear. The wheel search goes on...

I'm looking to buy some 18" Enkei RP03 rims I'm debating getting the 7.5" with 48mm offset which should be fine or the 8" wide rim with 45 offset, and what would be the best tire size for each, pretyt specific, I just started working at a tire place this week and will be purchasing wheels in a in the next few weeks and rimsby may, I only ask because I can get a really really good deal on Kumho Ecsta MX at wholesale and the wholesale prise is on sale lol, so I want to buy the tires now and the rims to slap em on later.

From what TG Posted:

18"

215/45R18 7.0"-8.0" 32 psi
225/40R18 7.5"-9.0" 38 psi
225/45R18 7.0"-8.5" 32 psi
235/40R18 8.0"-9.5" 33 psi
245/40R18 8.0"-9.5" 32 psi

If you want to run a 235 series tire, you will need the 8 inch wide rim. Other than that, it depends on what tire you want to run and its all about preference. Also, if you plan on rolling your fenders completely, you shouldnt have fitament problems with either rim.

Can someone tell me, I have 17" MOMO tuner wheels but i have no idea what the offset is. The stock tires are on them now and I'm wondering if I can get away with a 225/ wheel, and what aspect i should use?

P.S. I know NOTHING, if you cant tell

You should really look up the MOMO website and see if you can find your wheels and see what the offset might be. Without knowing anything AND TOTALLY GUESSING, If you have your stock wheels on and you are fine, as long as your 17" momo wheels have a 7 inch wide rim, you should be able to eyeball if you can run a 225 series tire. Look at the tire and picture how it will go with your suspension fully compressed. As long as it isnt dead close, you SHOULD be able to put a 225/45/17 on there.

Again, this isnt 100% fact because I dont know your offset and rim width, Im just making an educated assumption based on 17x7 being the standard rim size and since going from a 215/50/17 to a 225/45/17 is only a very minor change.

I have a set of 17x7.5 rims w/ +48 offset. Should I be able to use a 225/50 tire without rolling? I don't plan on lowering. I haven't seen anyone else with this particular setup. Thanx.

I was wondering if I can fit a 235/45 tire on a 17x8 ET48 rim. I'm going to try them next after my advan neovas wear out...lol. those tires look like r-comps..haha

That should work (at least the tire + rim combo is okay). You'll probably have to roll fenders.



Should be okay, but don't hold me to that!

Technically speaking, a 225/30/20 Pirelli P-Zero Nero has an overall rolling diameter of 25.5". That's only .1" off from the stock 25.6" O.D. on my MS6's 215/45/18's. That's about as good of a match as you can get in the tire world. +/- .2" is the recommend tolerance but +/- .4" is a very common occurance. 20's do not pose a problem, fitment wise, if the proper offset is achieved with the right wheel width. Shoulder profile varies from tire to tire as well which may help or hinder fender and control arm clearance.

The load rating on the same 225/30/20 is an 85, equivalent to 1235lbs per tire. Muultiply that by 4 tires gives you a total load rating of 4940lbs.

A 6i weighs about 3050lbs with my MS6 weighing in at 3600lbs. So on my heavier MS6 that leaves 1340 lbs for passengers and cargo.

Four extremely large 250lb adults would still leave you with room for 140lbs of cargo in the trunk or an average female passenger in the middle rear seat. Realistically speaking I only weigh 170lbs which leaves me 1170lbs for cargo and passengers. Remember, you have an additional 200-300lbs of load capacity if you're driving a non-turbo 4cyl or V6.

Plus, tire manufacturers conservatively buffer the load rating on a tire for safety reasons so they can actually handle more than they are rated for.

I personally wouldn't do a 20 but that's not to say that it can't be done successfully or safely. Heat causes tires to fail, so as long as you're not exceeding the load rating of all four tires or the speed rating for more than 20 minutes, such as towing a 2000lb boat at 320km/h for a 4 hour trip to Montreal, you should be fine. I'll bet you any money anyone who would do 20's probably rolls single or tandem most of the time and doesn't find himself in a car full of people with tons of cargo in the back.

dj petey, I don't know where you get your information, but you're way off base. First of all, we don't use curb weight to determine load rating of a tire to a specific vehicle. We use GVWR (Gross Vehicle Weight Rating). That means the tires must be capable of handling more load than the springs/suspension. GVWR is always much higher than curb weight.

Also, your reasoning is flawed because you're only taking into account static weight. You're not factoring in transfer loading which occurs while the vehicle is in motion. Under acceleration, braking and turning load shifts to the rear, front, left and right. When performing those maneuvers aggressively, the transfer loading increases. It's even more so when passengers and cargo are on board. It may not last long, but under those stress/load conditions, the tires must be able to handle that amount of load which is much higher than what you're talking about. The load is not distributed evenly.

The "reserve load" you refer to is not that the tires have more load than what the sidewall says, it's that we reduce the number on the sidewall by 10%. If that number still exceeds the GVWR, then you have a safely load rated tire for that vehicle. So, the 1235 on your 20s must be reduced to 1112. The GVWR is 4491 lbs. for the wagon (the heaviest model in the range). 1112 x 4 = 4448. Not enough. Plus, you'd have to run them at 50 psi just to get this amount of load. How many people do you know are going to drive around with their tires pumped to 50 psi all the time? Not going to happen. This is why I keep insisting that you maintain a load index of 91 or greater.

Should I trust a dealer's "what fits?" data on their homepages?

I'm going to buy wheels via internet because in my city (monterrey, mexico) we don't have a decent wheel dealer so i've been carefully reading all the info in the forums and on the web and mostly interested in pics of wheel mods on mazdas .

(btw... i own a 6i and so far, i'm particularly interested in König's Theory 18").