[KuroCX30]

Reference Chart:

General Tire Size Options:
Keep in mind that these are general size groups that I have curated that should be considered for tire sizing. Exact measurements of a tire vary within each size group depending on the tire type, brand and model. Always check the exact measurements at TireRack and the manufacturer's website before making a purchase. Extra caution should be taken with regards to the size groups that are squared in red. These sizes may or may not rub depending on the exact tire measurements, wheel width and wheel offset.

-------Sizes that Rub-------

29.3" - Instagram - 30on29s

• Falken Wildpeak A/T Trail 235/60
• Enkei TS-10 18"x8" +40mm
• Slight wheel well rub at full turn lock

29.1" - CX30 Talk - McMattface @McMattface

• Falken Wildpeak A/T Trail 235/65
• Enkei RPF1 17"x8" +35mm

29.0" - Facebook Mazda CX-30 Owners - Sergio Torres

• Falken Wildpeak A/T Trail 235/65
• Hyundai 16"x6.5" +46mm
• 30mm Lift Kit

28.9" - CX30 Talk - KuroCX30 or Instagram - KuroCX30

• Bridgestone Blizzak DM-V2 215/70
• Ray's Engineering Daytona M8 17"x7" +40

28.8" - CX30 Talk - Cocoloco

• Vredestein Quatrac Pro GT All-Season 225/55
• 2014-17 Mazda6 OEM 19"x7" +45

28.7" - Facebook Mazda CX-30 Owners - Kevin McFarland

• Falken Wildpeak A/T Trail 225/60
• Stock 18"x7" +45mm
• 40mm Lift Kit

28.7"- Facebook Mazda CX-30 Owners - Andrew Anderson

• Versatyre CRX4000 245/45
• Curva Concepts C42 20"x8.5" +35mm

-------Sizes that Clear-------

28.6" - Instagram - BayAreaMazda (no longer active)

• Falken Wildpeak AT3W 225/65
• KMC KM708 17"x8" +38mm

28.6" - CX30 Talk - KuroCX30 or Instagram - KuroCX30

• Falken Wildpeak A/T Trail 225/65
• Enkei RPF1 17"x7" +45mm

28.6" - Instagram - hiroshimaspirit

• Falken Wildpeak A/T Trail 225/65
• Fifteen52 Traverse MX 17"x8" +38mm

28.5" - CX30 Talk - KuroCX30 or Instagram - KuroCX30

• Michelin Pilot Sport 4 SUV 225/65
• Enkei RPF1 17"x8" +45mm

28.5" - Instagram - Joe Trevino @Copland Navi

• Nitto Nomad Grappler 225/65
• Falcon V2 17"x8" +30mm

28.1" - FB Mazda CX-30 Owners - Chris Howard
28.1" - FB Mazda CX-30 Owners - Keith Wagner

• Falken Wildpeak A/T Trail 235/55
• Enkei TFR 18"x8" +40mm

28.1" - CX30 Talk - lupineblue @lupineblue

• BFGoodrich Trail Terrain 104H 235/55
• Stock 18"x7" +45mm

28.1" - CX30 Talk - CX-30 Toy @CX30-TOY

• Michelin Crossclimate2 235/60
• Enkei PF05 17"x8" +30mm

28" - Instagram - Joe Trevino @Copland Navi

• Falken Wildpeak A/T Trail 215/65
• Falcon V2 17"x8" +30mm

27.9 " - Mazda CX-30 Club (North America) - Patrick Kelly

• General Grabber A/Tx 215/70
• 2010 Mazda3 OEM 16"x6.5" +50mm with spacers

27.9" - Instagram - jb74jl808 (username changed)

• BFGoodrich T/A KO2 215/70
• Delta Force Oval 16"x7" +35mm

27.9" - CX30 Talk - v24design or Instagram - v24design @v24design

• Toyo Open Country AT3 - 215/70
• Method MR502 Rally 16"x7" +30mm

27.7" - Instagram - mackeby184

• Goodyear F1 Assymetrical 5 245/45
• BBS CI-R 18"x8.5" +43mm

27.7" - CX30 Talk - Tom Servo @Tom Servo

• Continental ExtremeContact DWS06 Plus 245/45
• Niche Gamma M224 19"x8.5" +35mm

27.3" (OEM Tire Diameter)

Instagram - mazdacx30turbo

• Falken Wild Peak A/T Trail 235/50
• Konig Dekagram 18"x8.5" +45mm
• Slight rear suspension rub

Instagram - mazdacx30turbo

• Falken Wild Peak A/T Trail 235/50
• Fifteen52 Turbomac 18"x8.5" +30mm

CX30 Talk - key1cc

• Falken Wild Peak A/T Trail 235/50
• Stock 18"x7" +45mm

 

[Leo_B]

Very interesting chart. You might want to add 215/65-16 for the stock base model tire size.

 

[KuroCX30]

Very interesting chart. You might want to add 215/65-16 for the stock base model tire size.

Thanks. I added the stock base model tire size.

 

[KuroCX30]

Added an offset chart to estimate poke from stock for wheel widths of 7"-9". I included offset ranges that I have come across that others seem to be working with or what would potentially be possible.

 

[KuroCX30]

If anyone knows or can measure the distance of the stock 18x7 rim to the outer cladding, it may help everyone achieve flush fitment.

 

[McMattface]

That's what I was just about to ask.

My CX-30 should be arriving in about a week, hopefully less. I can try to do some measurements with the stock wheels/tires, and then we can make inferences off of that using the charts.

 

[KuroCX30]

1/16/22 edit: Updated the chart to include plus size owner example setups for reference. I think 1 of the 2 key measurements is the actual tire's hypotenuse measurement based on the tire's tread width and the tire's actual diameter. The other key measurement, if using a custom wheel, will be the 'poke from stock' measurement. Members have noted losing wheel well clearance distance when the wheel is pushed further outward, or running a wider tire. Estimated side wall heights highlighted in yellow are my personal opinion of what sidewall heights may aesthetically compliment the plastic cladding. If others have plus size setups they are running, please comment and I will add them to the chart.

 

[cocoloco]

Thanks for putting this together, super helpful!

 

[McMattface]

For the people who've testified that they've gotten some rub, do you know if any of them have discovered where the rub is happening? For example, is it the wheel well cover, the suspension, etc?

 

[KuroCX30]

For the people who've testified that they've gotten some rub, do you know if any of them have discovered where the rub is happening? For example, is it the wheel well cover, the suspension, etc?

Good question. So far, I've only encountered 2 cases of rub. 30on29s has experienced minor rub on the wheel well at full turn lock. I have not seen pictures of the rub to which he considers "slight" or "barely" to visually measure the degree at which the rub is occurring, so simply taking his word for it. He has also stated that adding spacers to the wheels made the issue worse so there's that as well.

There is also a fella who put 255/35/20 tires on TSW Aileron 20x10 +40 wheels. Without spacers, this would push the rim 33.1mm closer to the suspension, which indeed causes rub on the suspension parts. He applied spacers to his setup to prevent suspension rub and did not report any wheel well rub. I have not added his setup to the list because his overall diameter remained at 27". This setup seems extremes as far as wheel width and tire selection, which are stretched. His tires were swapped from a previous setup to save cost.

TLDR; So far I have found that pushing the wheel up to 19.1mm closer to the suspension is safe and 33.1mm causes rub. Where the limit lies, I do not know, but somewhere obviously between 19-33mm with regards to the wheel being closer to the suspension. This is why I used offsets in the chart that came close to 19mm closer to the suspension components.

 

[KuroCX30]

@McMattface - Added new columns that address suspension rub with an example. It appears that the closer the wheel to the suspension components the more likely that rub may occur. If we compare the BF Goodrich Trail Terrain on stock 18s vs the Falken Wild Peaks on Konig 18x8.5s, we see that the tire width and wheel offset dimensions are the same. The difference is the Konig 8.5 wheel width, which seems to be the culprit of the minor wheel rub on the strut. Owner states "dust cap was making slight contact but they're very flimsy so all I had to do was grab and spin the dust cap 180deg and it was fine". I would mind the limit of keeping the wheel less than 19mm closer to the suspension. If you are 19mm closer to the suspension, I would keep the tire width less than 9.6" in width. I'm also working on what offsets will push the wheel/tire beyond the fender. Tire selection will play a role here. Since the CX-30 and 3 are both shaped like an isosceles trapezoid, I think it's impossible to achieve flush with both front and rear wheels at the same time unless different offsets are used. The rear wheels are tucked in further vs the front wheels. Keeping the same offsets, I think finding an offset that creates balance between the front being a hair poked and the rear being a hair tucked is what I think would be best, although some might want the rear flush, while dealing with more poke in the front. Without doing any actual measurements, my preliminary conservative estimates based on wheel fitment recommendations, put this 'poke from stock' number at +7 to +12. +12 pushing the rear wheels more flush to the fender, again, estimated conservatively.
Examples of this would be:
7" wheel +38 to +33
7.5" wheel +45 to +40
8" wheel +51 to +46

235/50/18 Falken Wild Peaks on Konig Dekagram 18x8.5 +45 Rear

235/50/18 Falken Wild Peaks on Konig Dekagram 18x8.5 +45 Front

 

[cocoloco]

Thanks again for all the legwork you've done on this. I've gone down similar research rabbit holes but not as cohesively as you, so I appreciate it.

Basically my goal is to get the biggest possible tire on my cx-30 for aesthetic gap-reduction purposes without any rub or adding spacers. I will probably never off-road in this car so that's not a factor for me.

Inspired by a couple other users here I bought some of the mazda6 19" wheels from the 2014-2017 gen, they are 19x7.5 with a 45mm offset. I would love to run 235/55/19, but I worry that they're slightly too big. Also I believe that would be 7% bigger than stock which seems insane but I don't know. My backup would be 225/55/19 which seems like should work but that's bigger diameter-wise than any of our confirmed "no rub" setups which worries me a bit.

I'm looking at the vredestein quatrac pros based on recs here and that they seem to be a little lighter/smaller than contis/michelin, but I'm not tied to them.

For various reasons I probably won't be making the wheel/tire swap until May, even though I'd rather just get it over with. I'll be following along with the discussion here and will contribute however I can! Looking forward to figuring it out.

 

[KuroCX30]

Thanks again for all the legwork you've done on this. I've gone down similar research rabbit holes but not as cohesively as you, so I appreciate it.

Basically my goal is to get the biggest possible tire on my cx-30 for aesthetic gap-reduction purposes without any rub or adding spacers. I will probably never off-road in this car so that's not a factor for me.

Inspired by a couple other users here I bought some of the mazda6 19" wheels from the 2014-2017 gen, they are 19x7.5 with a 45mm offset. I would love to run 235/55/19, but I worry that they're slightly too big. Also I believe that would be 7% bigger than stock which seems insane but I don't know. My backup would be 225/55/19 which seems like should work but that's bigger diameter-wise than any of our confirmed "no rub" setups which worries me a bit.

I'm looking at the vredestein quatrac pros based on recs here and that they seem to be a little lighter/smaller than contis/michelin, but I'm not tied to them.

For various reasons I probably won't be making the wheel/tire swap until May, even though I'd rather just get it over with. I'll be following along with the discussion here and will contribute however I can! Looking forward to figuring it out.

I added the Vredestein Quatrac Pros to see where they would fall. You could check with your dealer and do what I'm going to attempt to do. Have your tire dealer order 2 sets of tires. Have them try the largest size first on one front wheel, check for rub at full turn lock. If no rub, mount the rest. If rub, drop down to the 225s and call it a day. Some places might charge you for an extra tire mount, hopefully not the tire. But it might be worth it to get the look you want and piece of mind to know what fits and what doesn't. The day my car comes in, I'm heading to the shop to change my wheels and tires, hopefully that is in the next month 🙏. I'll be testing 235/65/17 and 225/65/17 on a 7" wide wheel. If the the 235s fit, I'm all in. 🤞

 

[cocoloco]

That's awesome, thanks for doing that. Good idea with the two sizes, I'll have to ask them about that.

Hope your ride comes in soon!

 

[McMattface]

Just realized his avatar is this 🤣

 

[KuroCX30]

1/20/22 edit: Changed the calculations to use the 18" wheel and tire as the base from which other measurements are calculated. Added columns for Estimated Tire Poke From Stock and an Estimated Measurement of how much Closer the Tire is to the Suspension From Stock. These are estimates due to the relationship of how different sized tires sit on different sized wheels. Wheel width, offset and tire width should all be taken into consideration when estimating poke or the possibility of suspension rub. Hypotenuse length will be the bigger factor in determining wheel well rub, with offset playing a smaller role, imo.

 

[KuroCX30]

1/24/22 edit: Added some examples. Moved rare sizes to the bottom and included number of tires available at tirerack.com for each size. Added columns for tire weight, speed and load, along with columns for wheel weight and load. 2 columns compare weights of new setups to stock setups.

 

[McMattface]

You read my mind! I was just looking into the availability of the various tire sizes to help me determine the practicality of going with one size over others.

Random side note, my CX-30 delivery was delayed by another month after a call yesterday. Some issue with the with title transfer from New Mexico to Colorado 💀

 

[KuroCX30]

1/25/22 edit: Adjusted the overall tire width (Section Width) to more accurately reflect the relationship between the tire specs measured rim width and the rim it is mounted on in each example. The industry rule of thumb is that for every 1/2" change in rim width, the tire's section width will correspondingly change by approximately 2/10". The numbers were adjusted to more accurately represent each setup. The rear rub with the 235/50r18 Falken Wild Peak A/T Trail on 18x8.5 occurred due to the wider wheel. The section width of that tire was measured on a 7.5" wheel. Mounting it on a 8.5" wheel increases the section width by 0.4", equaling 10". The owner previously had 245/45r18 Pilot Sport A/S3+ on the same wheels with 9.6" section width measured on a 8" wheel, which bumped the actual section width to 9.8". 9.8" cleared, 10" did not. This was a difference of having the side wall 11.5mm closer to the suspension (clear), vs 14mm closer to the suspension (rub). Another step closer to dialing this project in.

You read my mind! I was just looking into the availability of the various tire sizes to help me determine the practicality of going with one size over others.

Random side note, my CX-30 delivery was delayed by another month after a call yesterday. Some issue with the with title transfer from New Mexico to Colorado 💀

I figured it would be useful to weed out some of the useless sizes when determining what sizes to look for and choose from.

 

[Seanhfx]

Huge props to OP on this thread! I've bought Michelin Pilot AS 4 tires to replace the stock tires and will likely be going with new RIMS 18x8 +45 ET on 235/50/18. According to the calcs, the scrub radius remains the same at zero, and 12.7mm closer to the suspension and out (poke). A 40 ET on 18x8 would poke out 18 mm and in 7mm, with a slightly more positive scrub.

I was looking at the stock setup, and there doesn't seem to be much room in the rear to the suspension but searching this forum, lots have seemed to go with this setup. Likely going with Fast Innovation wheels, hubcentric. Once spring arrives and I get them on, I will report back. Can't wait!