225/40R18 vs 235/45R18: Gas Mileage & Performance Comparison
* Below is a comparison table. Assuming 2 tires of the same manufacturer, material and tested on the same road conditions.
| 235/45R18 | 225/40R18 | |
| Wet/Snowy Roads | Reduced Traction | Better Traction |
| Rough Terrain | Smoother Ride | Reduced Stability |
| Handling/Steering | Better | Less Responsive |
| Gas Mileage | Better | Good |
| Road Noise | Quiet | Quieter |
| Cost | More Expensive | Less Expensive |
Can You Replace The 235/45R18 With The 225/40R18?
No, both tires have the same rim diameter, but the 225/40R18 has a smaller overall diameter than the 235/45R18 which is -4.94% (1.24-inch).
When you want to replace a different tire size, as a rule, for the rim diameter, you will need to be sure that your tires and rims are an exact match, e.g. a 235/45R18 tire will only fit on a 18″ diameter rim.
You Can check our tools and charts below to find your size:
