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BMW 440i tire upsize & plus-size guide

Every safe upsize, plus-size, wider, and winter-narrower option for the BMW 440i; covering all 3 of its factory tire sizes, each inside the ETRTO ±3% overall-diameter tolerance, with speedometer impact and catalog availability per size.

By Mark Bishop · Last verified 2026-05-17 · BMW 440i fitment specs

This guide takes the factory tire sizes of the BMW 440i and shows every geometrically valid alternative; the plus-sizes that fill the wheel arch, the wider sizes that add grip, and the narrower winter sizes that bite through snow. All math is derived from the ±3% ETRTO safe-fit rule, not scraped listings.

225/45R18; factory fitment (2017–2020)

Overall diameter 659.7 mm (25.97 in). Alternatives below are grouped by upgrade intent; every one is inside the ±3% safe-fit envelope for this size.

Plus-1 (next rim size up)

Plus-1 keeps overall diameter constant while bumping rim diameter by one inch and dropping aspect ratio by ten points. The standard daily-driver upgrade; sharper steering response, mild ride penalty, modest tire-cost premium.

SizeOD (mm)True @ 60 mphVerdictIn catalog
255/35R19 661 0.21% 60.13 mph Safe Yes
195/45R19 658 -0.24% 59.85 mph Safe -
225/40R19 663 0.44% 60.26 mph Safe -
215/40R19 655 -0.77% 59.54 mph Safe -
245/35R19 654 -0.85% 59.49 mph Safe Yes
205/45R19 667 1.12% 60.67 mph Within tolerance -
235/40R19 671 1.65% 60.99 mph Within tolerance Yes
235/35R19 647 -1.91% 58.85 mph Within tolerance Yes
205/40R19 647 -1.99% 58.81 mph Within tolerance -
215/45R19 676 2.49% 61.49 mph Within tolerance -
195/50R19 678 2.71% 61.63 mph Within tolerance -
245/40R19 679 2.86% 61.72 mph Within tolerance Yes
225/35R19 640 -2.97% 58.22 mph Within tolerance -

Plus-2 (two rim sizes up)

Plus-2 lifts rim diameter by two inches with a twenty-point aspect drop. Noticeable ride penalty, higher pothole risk, and a meaningful tire-cost premium. Suitable for performance trims and aesthetic upgrades.

SizeOD (mm)True @ 60 mphVerdictIn catalog
215/35R20 659 -0.18% 59.89 mph Safe -
255/30R20 661 0.20% 60.12 mph Safe Yes
195/40R20 664 0.65% 60.39 mph Safe -
245/30R20 655 -0.71% 59.57 mph Safe -
225/35R20 666 0.88% 60.53 mph Safe -
205/35R20 652 -1.24% 59.25 mph Within tolerance -
235/30R20 649 -1.62% 59.03 mph Within tolerance -
205/40R20 672 1.86% 61.12 mph Within tolerance -
235/35R20 673 1.94% 61.16 mph Within tolerance Yes
195/35R20 645 -2.30% 58.62 mph Within tolerance -
225/30R20 643 -2.53% 58.48 mph Within tolerance -

Same rim, wider footprint

Same rim diameter as your OEM, just a wider footprint. Increases grip and footprint contact at the cost of fuel economy and steering effort. Confirm fender clearance at full lock before purchase.

SizeOD (mm)True @ 60 mphVerdictIn catalog
255/40R18 661 0.23% 60.14 mph Safe Yes
245/40R18 653 -0.99% 59.41 mph Safe Yes
235/45R18 669 1.36% 60.82 mph Within tolerance Yes
235/40R18 645 -2.20% 58.68 mph Within tolerance Yes
245/45R18 678 2.73% 61.64 mph Within tolerance Yes

Winter / narrower contact

Narrower than OEM, aspect ratio raised to preserve overall diameter. Higher contact pressure improves snow and slush bite; the Nokian-style rule of one width step down for winter on the same overall diameter.

SizeOD (mm)True @ 60 mphVerdictIn catalog
205/55R17 657 -0.36% 59.78 mph Safe Yes
205/50R18 662 0.38% 60.23 mph Safe -
195/60R17 666 0.92% 60.55 mph Safe -
195/50R18 652 -1.14% 59.32 mph Within tolerance -
215/55R17 668 1.30% 60.78 mph Within tolerance Yes
215/45R18 651 -1.36% 59.18 mph Within tolerance -
195/55R18 672 1.82% 61.09 mph Within tolerance -
215/50R18 672 1.89% 61.14 mph Within tolerance -
215/50R17 647 -1.96% 58.83 mph Within tolerance -
195/55R17 646 -2.03% 58.78 mph Within tolerance -
205/45R18 642 -2.73% 58.36 mph Within tolerance -
205/60R17 678 2.74% 61.65 mph Within tolerance -

Other geometric alternatives

Geometrically valid alternatives that don't fit a named category. Often combinations of rim and aspect change that happen to land in tolerance.

SizeOD (mm)True @ 60 mphVerdictIn catalog
195/65R16 660 0.03% 60.02 mph Safe -
255/45R17 661 0.24% 60.15 mph Safe -
255/50R16 661 0.26% 60.15 mph Safe -
225/50R17 657 -0.44% 59.74 mph Safe Yes
215/60R16 664 0.71% 60.43 mph Safe Yes
235/55R16 665 0.79% 60.47 mph Safe -
225/55R16 654 -0.88% 59.47 mph Safe -
235/50R17 667 1.08% 60.65 mph Within tolerance -
205/60R16 652 -1.11% 59.34 mph Within tolerance Yes
245/45R17 652 -1.12% 59.33 mph Within tolerance -
245/50R16 651 -1.26% 59.25 mph Within tolerance -
205/65R16 673 2.00% 61.20 mph Within tolerance -
245/55R16 676 2.46% 61.47 mph Within tolerance -
235/45R17 643 -2.49% 58.51 mph Within tolerance -
225/60R16 676 2.53% 61.52 mph Within tolerance -
215/55R16 643 -2.55% 58.47 mph Within tolerance Yes
245/50R17 677 2.59% 61.56 mph Within tolerance -
235/50R16 641 -2.77% 58.34 mph Within tolerance -
195/60R16 640 -2.93% 58.24 mph Within tolerance -
225/55R17 679 2.97% 61.78 mph Within tolerance Yes

225/50R17; factory fitment (2017–2018)

Overall diameter 656.8 mm (25.86 in). Alternatives below are grouped by upgrade intent; every one is inside the ±3% safe-fit envelope for this size.

Plus-1 (next rim size up)

Plus-1 keeps overall diameter constant while bumping rim diameter by one inch and dropping aspect ratio by ten points. The standard daily-driver upgrade; sharper steering response, mild ride penalty, modest tire-cost premium.

SizeOD (mm)True @ 60 mphVerdictIn catalog
225/45R18 660 0.44% 60.26 mph Safe Yes
245/40R18 653 -0.55% 59.67 mph Safe Yes
255/40R18 661 0.67% 60.40 mph Safe Yes
195/50R18 652 -0.70% 59.58 mph Safe -
205/50R18 662 0.82% 60.49 mph Safe -
215/45R18 651 -0.93% 59.44 mph Safe -
235/40R18 645 -1.77% 58.94 mph Within tolerance Yes
235/45R18 669 1.81% 61.09 mph Within tolerance Yes
195/55R18 672 2.27% 61.36 mph Within tolerance -
205/45R18 642 -2.30% 58.62 mph Within tolerance -
215/50R18 672 2.34% 61.41 mph Within tolerance -
225/40R18 637 -2.98% 58.21 mph Within tolerance Yes

Plus-2 (two rim sizes up)

Plus-2 lifts rim diameter by two inches with a twenty-point aspect drop. Noticeable ride penalty, higher pothole risk, and a meaningful tire-cost premium. Suitable for performance trims and aesthetic upgrades.

SizeOD (mm)True @ 60 mphVerdictIn catalog
195/45R19 658 0.20% 60.12 mph Safe -
215/40R19 655 -0.33% 59.80 mph Safe -
245/35R19 654 -0.41% 59.75 mph Safe Yes
255/35R19 661 0.65% 60.39 mph Safe Yes
225/40R19 663 0.88% 60.53 mph Safe -
235/35R19 647 -1.48% 59.11 mph Within tolerance Yes
205/40R19 647 -1.55% 59.07 mph Within tolerance -
205/45R19 667 1.57% 60.94 mph Within tolerance -
235/40R19 671 2.10% 61.26 mph Within tolerance Yes
225/35R19 640 -2.54% 58.47 mph Within tolerance -
195/40R19 639 -2.77% 58.34 mph Within tolerance -
215/45R19 676 2.94% 61.76 mph Within tolerance -

Same rim, wider footprint

Same rim diameter as your OEM, just a wider footprint. Increases grip and footprint contact at the cost of fuel economy and steering effort. Confirm fender clearance at full lock before purchase.

SizeOD (mm)True @ 60 mphVerdictIn catalog
245/45R17 652 -0.69% 59.59 mph Safe -
255/45R17 661 0.69% 60.41 mph Safe -
235/50R17 667 1.52% 60.91 mph Within tolerance -
235/45R17 643 -2.06% 58.77 mph Within tolerance -

Winter / narrower contact

Narrower than OEM, aspect ratio raised to preserve overall diameter. Higher contact pressure improves snow and slush bite; the Nokian-style rule of one width step down for winter on the same overall diameter.

SizeOD (mm)True @ 60 mphVerdictIn catalog
205/55R17 657 0.08% 60.05 mph Safe Yes
195/65R16 660 0.47% 60.28 mph Safe -
205/60R16 652 -0.67% 59.60 mph Safe Yes
215/60R16 664 1.16% 60.69 mph Within tolerance Yes
195/60R17 666 1.37% 60.82 mph Within tolerance -
215/50R17 647 -1.52% 59.09 mph Within tolerance -
195/55R17 646 -1.60% 59.04 mph Within tolerance -
215/55R17 668 1.75% 61.05 mph Within tolerance Yes
215/55R16 643 -2.12% 58.73 mph Within tolerance Yes
205/65R16 673 2.45% 61.47 mph Within tolerance -
195/60R16 640 -2.50% 58.50 mph Within tolerance -

Other geometric alternatives

Geometrically valid alternatives that don't fit a named category. Often combinations of rim and aspect change that happen to land in tolerance.

SizeOD (mm)True @ 60 mphVerdictIn catalog
195/70R15 654 -0.43% 59.74 mph Safe -
225/55R16 654 -0.44% 59.74 mph Safe -
215/65R15 661 0.56% 60.34 mph Safe -
255/50R16 661 0.70% 60.42 mph Safe -
255/55R15 662 0.72% 60.43 mph Safe -
245/50R16 651 -0.82% 59.51 mph Safe -
225/60R15 651 -0.88% 59.47 mph Safe -
235/60R15 663 0.94% 60.57 mph Safe -
245/55R15 651 -0.96% 59.42 mph Safe -
235/55R16 665 1.23% 60.74 mph Within tolerance -
205/65R15 648 -1.42% 59.15 mph Within tolerance -
205/70R15 668 1.71% 61.02 mph Within tolerance -
235/50R16 641 -2.34% 58.59 mph Within tolerance -
225/65R15 674 2.54% 61.53 mph Within tolerance -
235/55R15 640 -2.63% 58.42 mph Within tolerance -
215/60R15 639 -2.71% 58.37 mph Within tolerance -
245/60R15 675 2.77% 61.66 mph Within tolerance -
245/55R16 676 2.91% 61.74 mph Within tolerance -
225/60R16 676 2.98% 61.79 mph Within tolerance -

225/40R19; factory fitment (2018)

Overall diameter 662.6 mm (26.09 in). Alternatives below are grouped by upgrade intent; every one is inside the ±3% safe-fit envelope for this size.

Plus-1 (next rim size up)

Plus-1 keeps overall diameter constant while bumping rim diameter by one inch and dropping aspect ratio by ten points. The standard daily-driver upgrade; sharper steering response, mild ride penalty, modest tire-cost premium.

SizeOD (mm)True @ 60 mphVerdictIn catalog
195/40R20 664 0.21% 60.13 mph Safe -
255/30R20 661 -0.24% 59.86 mph Safe Yes
225/35R20 666 0.44% 60.26 mph Safe -
215/35R20 659 -0.62% 59.63 mph Safe -
245/30R20 655 -1.15% 59.31 mph Within tolerance -
205/40R20 672 1.42% 60.85 mph Within tolerance -
235/35R20 673 1.49% 60.90 mph Within tolerance Yes
205/35R20 652 -1.68% 58.99 mph Within tolerance -
235/30R20 649 -2.05% 58.77 mph Within tolerance -
245/35R20 680 2.55% 61.53 mph Within tolerance -
215/40R20 680 2.63% 61.58 mph Within tolerance -
195/35R20 645 -2.73% 58.36 mph Within tolerance -
225/30R20 643 -2.96% 58.23 mph Within tolerance -

Plus-2 (two rim sizes up)

Plus-2 lifts rim diameter by two inches with a twenty-point aspect drop. Noticeable ride penalty, higher pothole risk, and a meaningful tire-cost premium. Suitable for performance trims and aesthetic upgrades.

SizeOD (mm)True @ 60 mphVerdictIn catalog
215/30R21 662 -0.03% 59.98 mph Safe -
255/25R21 661 -0.26% 59.85 mph Safe -
225/30R21 668 0.88% 60.53 mph Safe -
205/30R21 656 -0.94% 59.44 mph Safe -
245/25R21 656 -1.01% 59.39 mph Within tolerance -
195/35R21 670 1.10% 60.66 mph Within tolerance -
235/25R21 651 -1.77% 58.94 mph Within tolerance -
235/30R21 674 1.78% 61.07 mph Within tolerance -
195/30R21 650 -1.84% 58.90 mph Within tolerance -
205/35R21 677 2.16% 61.29 mph Within tolerance -
225/25R21 646 -2.52% 58.49 mph Within tolerance -
245/30R21 680 2.69% 61.61 mph Within tolerance -

Same rim, wider footprint

Same rim diameter as your OEM, just a wider footprint. Increases grip and footprint contact at the cost of fuel economy and steering effort. Confirm fender clearance at full lock before purchase.

SizeOD (mm)True @ 60 mphVerdictIn catalog
255/35R19 661 -0.23% 59.86 mph Safe Yes
235/40R19 671 1.21% 60.72 mph Within tolerance Yes
245/35R19 654 -1.28% 59.23 mph Within tolerance Yes
235/35R19 647 -2.34% 58.60 mph Within tolerance Yes
245/40R19 679 2.41% 61.45 mph Within tolerance Yes

Winter / narrower contact

Narrower than OEM, aspect ratio raised to preserve overall diameter. Higher contact pressure improves snow and slush bite; the Nokian-style rule of one width step down for winter on the same overall diameter.

SizeOD (mm)True @ 60 mphVerdictIn catalog
205/50R18 662 -0.06% 59.96 mph Safe -
195/45R19 658 -0.68% 59.59 mph Safe -
205/45R19 667 0.68% 60.41 mph Safe -
215/40R19 655 -1.21% 59.28 mph Within tolerance -
195/55R18 672 1.37% 60.82 mph Within tolerance -
215/50R18 672 1.45% 60.87 mph Within tolerance -
195/50R18 652 -1.57% 59.06 mph Within tolerance -
215/45R18 651 -1.80% 58.92 mph Within tolerance -
215/45R19 676 2.04% 61.22 mph Within tolerance -
195/50R19 678 2.26% 61.36 mph Within tolerance -
205/40R19 647 -2.41% 58.55 mph Within tolerance -

Other geometric alternatives

Geometrically valid alternatives that don't fit a named category. Often combinations of rim and aspect change that happen to land in tolerance.

SizeOD (mm)True @ 60 mphVerdictIn catalog
255/45R17 661 -0.20% 59.88 mph Safe -
255/40R18 661 -0.21% 59.87 mph Safe Yes
225/45R18 660 -0.44% 59.74 mph Safe Yes
195/60R17 666 0.48% 60.29 mph Safe -
235/50R17 667 0.63% 60.38 mph Safe -
205/55R17 657 -0.80% 59.52 mph Safe Yes
215/55R17 668 0.86% 60.52 mph Safe Yes
225/50R17 657 -0.88% 59.47 mph Safe Yes
235/45R18 669 0.92% 60.55 mph Safe Yes
245/40R18 653 -1.42% 59.15 mph Within tolerance Yes
245/45R17 652 -1.55% 59.07 mph Within tolerance -
245/50R17 677 2.14% 61.29 mph Within tolerance -
245/45R18 678 2.28% 61.37 mph Within tolerance Yes
205/60R17 678 2.29% 61.38 mph Within tolerance -
215/50R17 647 -2.38% 58.57 mph Within tolerance -
195/55R17 646 -2.46% 58.52 mph Within tolerance -
225/55R17 679 2.52% 61.51 mph Within tolerance Yes
235/40R18 645 -2.63% 58.42 mph Within tolerance Yes
235/45R17 643 -2.91% 58.25 mph Within tolerance -
225/50R18 682 2.96% 61.77 mph Within tolerance -

Which upsize path fits your priorities?

Every option on this page is inside the ETRTO ±3% overall-diameter tolerance, so any of them is mechanically safe on the factory rim geometry. The difference is what each trades. Use this to pick the category, then read the verdict table above for the exact sizes.

CategoryRide comfortHandlingFuel economyRoad noiseTire cost
Plus-1Slightly firmerSharper≈ neutral≈ neutralModest premium
Plus-2FirmerSharpestSlightly worseSlightly higherHigher premium
Wider (same rim)≈ neutralMore gripSlightly worseSlightly higherModest premium
Winter narrowerSofterSofter dry≈ neutralLower≈ neutral
Narrower (same rim)SofterLess gripBetterLowerOften cheaper
OEM-equivalent≈ OEM≈ OEM≈ OEM≈ OEM≈ OEM

"≈" means no meaningful change versus the factory size. Comfort and noise assume the same tire model and load rating; switching brand or category (touring → performance) usually moves these more than the size change does.

Winter setup for the BMW 440i

For winter, the European engineering rule is to step down one width while raising aspect ratio to hold the same overall diameter; the "Winter / narrower contact" rows in the table above. A narrower footprint concentrates the vehicle's weight over less rubber, raising contact pressure so the tread bites through snow and slush instead of floating on it. Keep the overall diameter within ±3% of 225/45R18 so ABS, TPMS, and (on AWD trims) the center coupling stay inside their factory calibration. Fit four matching winter tires, never two.

FAQ

Can I put bigger tires on my BMW 440i?
Yes; within limits. Any size in the tables above is inside the ETRTO ±3% overall-diameter tolerance, which keeps speedometer, TPMS, and ABS calibration intact. The Plus-1 category is the standard bigger-wheel upgrade; Plus-2 is the aesthetic/performance maximum. Sizes beyond ±3% are excluded because they push those systems out of factory range and can rub at full steering lock.
What is the OEM tire size for the BMW 440i?
The BMW 440i shipped with 3 distinct factory tire sizes across its years and trims; each is listed above as its own section with the alternatives for that size. 225/45R18 is the most common. Check the door-jamb placard or your owner's manual for your specific year and trim.
Will bigger tires hurt my BMW 440i's fuel economy or ride?
Plus-1 is close to neutral on both. Plus-2 and wider sizes add rotating mass and footprint, which costs a little fuel economy and ride comfort for sharper steering and grip. The decision matrix above shows the trade-off per category. Staying within ±3% overall diameter means the transmission and speedometer are unaffected.
Do I need new wheels to change tire size on my BMW 440i?
Not for same-rim changes (wider, narrower, winter-narrower keep your factory rim diameter). Plus-1 and Plus-2 raise rim diameter and require wheels in the new diameter with a compatible bolt pattern and offset; check the wheel bolt-pattern page linked below before buying.

Sources & methodology

Last verified 2026-05-17 against the standards below.

  1. ETRTO 2024 Standards Manual §2.3 (section width, aspect ratio, overall diameter formula). European Tyre and Rim Technical Organisation, Brussels.
  2. SAE J1349 (speedometer accuracy reference envelope).
  3. NHTSA FMVSS 138 Tire Pressure Monitoring Systems; rev/mile calibration requirements.
  4. Tire Industry Association Technical Bulletin TB-2019-04 (plus-sizing guidance).
  5. Nokian Tyres "Why winter tyres should be narrower" technical bulletin, 2019.