Which is more fuel-efficient, 175 or 185 tires?
2 Answers
175 tires have a smaller contact area compared to 185 tires, resulting in less friction and therefore better fuel efficiency. Here is an introduction to tires: 1. Tire width: A larger tire contact area increases rolling resistance, leading to higher fuel consumption; 2. Supporting vehicle load: The vehicle's weight causes the tire to compress until the average pressure on the contact area balances with the internal inflation pressure. Below are additional factors to consider when increasing tire width: 1. Local traffic regulations (ensuring compliance for annual inspections, vehicle warranties, etc.); 2. Tire speed and load index; 3. Rim specifications, such as width and offset; 4. Space constraints; 5. Vehicle suspension system; 6. (Important) Maintaining the tire's load radius.
Having driven for over a decade, I've noticed that tire width does affect fuel consumption. The 175 tires are narrower, with lower rolling resistance, lighter weight, and reduced air resistance, making them theoretically more fuel-efficient. In comparison, the 185 tires are wider, offering better traction, especially on wet or slippery roads, but the increased friction slightly raises fuel consumption. In practice, fuel savings depend on your vehicle's weight, tire pressure, and driving habits—for example, maintaining a steady speed has a more significant impact on fuel efficiency than sudden acceleration. I recommend prioritizing the tire size suggested in your vehicle's manual. The 175 tires are ideal for small cars focused on economy, but if you frequently drive on highways or carry heavy loads, the 185 tires might offer a better overall balance, avoiding safety compromises for the sake of fuel savings. Remember to check tire pressure regularly, as keeping it within the optimal range can further enhance fuel efficiency—don’t focus solely on tire size.
