TireSizeCalculator .site Precision Fitment & Wheel Lab
Wheel Upgrade Fitment

Plus-Size Tire Calculator: +1, +2 & +3 Rim Upgrades

Upgrading to bigger wheels? Find the exact lower aspect ratio tire that maintains your factory rolling diameter within factory tolerances.

Equivalent Low-Profile Fitment Finder

Base Diameter: 24.88 inches

Compatible Low-Profile Tire Options:

Plus-Sizing Engineering & Performance Physics

What is Plus-1?

Plus-1 increases wheel diameter by 1 inch (e.g. 16" to 17") while lowering the sidewall aspect ratio (e.g. 55 to 45). The overall tire height stays identical, maintaining your speedometer calibration while improving cornering responsiveness.

What is Plus-2?

Plus-2 goes up 2 inches in rim diameter (e.g. 16" to 18"). The tire sidewall becomes noticeably thinner (aspect ratio 40 or 35). This gives an aggressive sporty aesthetic and sharp steering feedback, with slightly firmer ride quality over potholes.

Load Capacity Safety

When reducing tire sidewall height, always ensure the new tire's Load Index meets or exceeds your vehicle's factory OEM specification to avoid blowout risks under heavy passenger or cargo loading.

Plus size tire fitment geometry diagram showing low profile aspect ratio and large wheel diameter dimensional balance
Plus-Size Geometry Blueprint
Low-Profile Plus Sizing: Increasing wheel diameter while reducing sidewall aspect ratio preserves outer rolling diameter while boosting lateral steering stiffness.
Plus-1 / Plus-2 Sizing

Big Brake Clearance & Rotational Inertia Dynamics

Plus-sizing is often required when installing upgraded multi-piston big brake kits (BBKs) to ensure clearance over the caliper barrel and rotor hats.

However, larger cast wheels increase unsprung rotational mass. Every pound of rotating wheel weight affects suspension responsiveness as much as 2 pounds of static vehicle chassis weight. Consider flow-formed or forged aluminum wheels to preserve suspension compliance.

Frequently Asked Questions About Plus-Sizing Tires

What does Plus-1, Plus-2, and Plus-3 wheel sizing mean?
Plus-sizing refers to increasing the wheel rim diameter by 1, 2, or 3 inches while proportionally reducing the tire's sidewall aspect ratio. This ensures the total outer rolling diameter remains within ±1.5% of factory baseline, protecting speedometer accuracy, ABS sensors, and transmission shift timing.
Does plus-sizing affect ride comfort and road noise?
Yes. Thinner sidewalls (such as 35 or 40 series profiles) offer less pneumatic compliance to absorb potholes and highway seams. While handling sharpness, turn-in speed, and steering feel increase dramatically, ride stiffness is noticeably firmer.
How do I protect load carrying capacity when plus-sizing?
Because lower profile tires hold a smaller volume of air, you must verify that the replacement tire's Load Index rating matches or exceeds your OEM door placard rating. Most plus-sized low-profile tires require 'Extra Load' (XL / RF) specification to carry full vehicle weight.
Will plus-sizing hurt fuel economy or acceleration?
Larger alloy wheels and wider low-profile tires are generally heavier, concentrating rotational mass further from the axle centerline. This increases rotational inertia, which can cause a small 2-4% decrease in city fuel economy and slight deceleration drag.