Myth: Keeping tires inflated above their recommended pressure will help maintain a car's optimum fuel consumption. Fact: Every five pounds per square inch (psi) of tire pressure you lose can translate into a two per cent loss of gas mileage.
The short answer: yes. Tires can make a big difference in the number of miles a driver gets to a tank of gas. In fact, 20% to 30% of a vehicle's fuel consumption and 24% of road vehicle CO2 emissions are tire-related.
Under inflated tyres increase your vehicle's drag, which increases fuel consumption. But by how much exactly? A study by the National Highway Traffic Safety Administration (NHTSA) in the USA found that every 1 per cent decrease in tyre pressure correlated to a 0.3 per cent reduction in fuel economy.
If your car is underinflated, then it is going to feel sluggish. Underinflation will also lower the fuel economy of your car and shorten the lifespan of a tire. Overinflating a tire will also shorten its lifespan. The car will also handle more poorly because less of the tire is in contact with the road.
Fully Inflated Tires are Safer
Besides saving fuel and money and minimizing emissions, proper tire inflation is safer and less likely to fail at high speeds. Under-inflated tires make for longer stopping distances and will skid longer on wet surfaces. Properly inflated tires will last longer as they wear more evenly.
Higher inflated tires cannot isolate road irregularities well, causing them to ride harsher. However, higher inflation pressures usually provide an improvement in steering response and cornering stability up to a point.
What Is a Good Tire Pressure? The typical range for good tire pressure is 32 to 40 psi on a couple of tires. But, the appropriate pressure for your car will differ depending on the vehicle's weight and load capability.
Most passenger cars' psi requirement will be between 30 to 35 psi, but several vehicles fall outside of that range and every vehicle will have specific requirements. Good tire air pressure ensures that tires wear evenly, provide a smooth ride, and increase fuel efficiency.
Recommended tire pressure
Based on normal tire sizes for each segment, small-sized car are usually 30 psi, medium-sized cars are 36 psi, and large cars are 42 psi. Keep in mind that warm tires normally exceed recommended cold tire pressures by 4-6 psi.
The short answer is that when they service and change your oil the tires are generally hot. The PSI in your door is for cold (car has sat overnight). If your tires are hot the pressure will be higher than cold. Thus when they fill the tires they do so to the appropriate “hot” level.
Drive carefully
Good driving habits can help to improve your fuel efficiency. Avoid hitting down hard on the accelerator and braking late. Driving at high speeds also increases your fuel consumption. After about 60 mph, your fuel efficiency drops a lot.
As tyres account for 20% of a car's overall fuel consumption, choosing wisely here can give significant savings. The more miles you do, the more money a fuel-efficient tyre will save.
Pressing the accelerator pedal gently will help you save gas. Following this rule of thumb allows for more efficient driving. Aim to take about five seconds to accelerate your vehicle up to 15 miles per hour from a stop. For a manual transmission, use a moderate throttle position and shift between 2000 and 2500 rpm.
Wide tires provide for more friction, making your vehicle consume more fuel, whereas narrow tires cause your car to consume less fuel because they have lower amounts of friction.
The greater the thermal efficiency of an engine — the more energy that an engine converts into mechanical energy — the greater the engine's fuel efficiency. Compression engines have a higher thermal efficiency because they have higher compression ratios.
The 4psi rules states that “if your tyres are inflated correctly then the tyre pressure measured when the tyres are hot (after travel) will be 4psi greater than the pressure measured when they were cold (before travel)”.
Ideal Tire Pressure
Tire pressure between 32 to 35 PSI is most suitable for most vehicles. However, one can go as low as 20 PSI (although that is not recommended). Anything below 20 PSI is considered a flat tire. PSI stands for Pounds per Square Inch.
Yes, it can. You can find the difference in grip level, braking, acceleration, tyre wear, mileage. Pretty much everything.
In most of these cases, 40 psi should be more than enough, and since most modern tire designs will allow up to 44 psi (in some cases more) this is not a problem. If you have a heavily loaded vehicle, up to 44 or even higher is ok if the tire allows it, but this is a little high for most vehicles.
As a general rule, the ideal tire pressure is between 30 and 35 PSI (pounds per square inch), but not all cars are alike.
Fifty psi is a lot of pressure for a passenger-car tire. That number is on the sidewall because it's the tire's maximum allowable pressure. That means you can put up to 50 pounds of air in that tire without worrying about the tire exploding or deforming to the point where the car won't handle safely.
As long as you stay below the maximum tire pressure listed on the tire's sidewall (which is different from the recommended pressure), you can overinflate your tires by 10 percent or even more without too much concern.
Tyres filled to their maximum psi become rigid making them more susceptible to damage from potholes or curbs. Excessive air pressure not only makes them more prone to premature wear and tear but can also deform the shape of the tyre. This results in reduced traction and poor grip thus causing the tyre to bulge.
Here's how heat impacts your tire pressure:
In general, tires lose or gain 1 PSI (pound per square inch) for every 10℉ change in temperature. Theoretically, your tires could gain 2 PSI over the course of the day if the temperature rises 20℉—a real possibility in many parts of the country.