Properly inflated tires are important for safe driving and good fuel economy. But what if you don’t have a tire pressure gauge?
There are a few simple techniques you can use to check if your tires look properly inflated without actually measuring the PSI. While these aren’t extremely precise methods, they can give you a general sense if there’s an issue that needs addressing.
7 Best Ways To Check Tire Pressure Without a Gauge
PSI Check
PSI (pounds per square inch) is the actual measurement of air pressure inside a tire. Most vehicles have a recommended PSI printed on a sticker inside the driver’s side door jamb or in the owner’s manual. For example, the manufacturer may recommend inflation of 32-35 PSI.
Without a pressure gauge, you won’t be able to measure the exact PSI. But there are some basic checks you can do visually and by feel to get a general sense if the tires are around the proper inflation level.
Hand Pressure
One simple way to check is to use your hands to feel the firmness of each tire. Start by pressing down on the sidewall with an open palm. A properly inflated tire should feel firm and resist the pressure. If the side wall gives too easily under your hand, that likely signals under-inflation.
You can also try poking each tire with an extended index finger, applying light pressure. On a firm, inflated tire, you should not be able to make much of an indentation. If your finger sinks in deeply, that’s an indication of under-inflation.
Of course this hand pressure check requires having a good memory of what a properly inflated tire should feel like. So it works best if you check all four tires, then compare the relative firmness. The softer tires likely need additional PSI.
Cargo Check
Take note of how much the vehicle sinks down on its wheels when loaded up with cargo and passengers. When properly inflated, the tires should bulge out a bit under the weight load, but the wheel wells shouldn’t look drastically lowered.
If the vehicle looks like it’s sinking and sagging on its wheels when loaded up, that’s a sign the tire pressures are probably too low. In essence, partially deflated tires will have less air volume inside to help hold up the heavier weight.
Ride Over Mud
Here’s another good visual check you can make if you happen to drive over a muddy or snow-covered area. Properly inflated tires will have good tread contact, leaving a consistent trail pattern in the mud or snow. But an under-inflated tire sidewall will bulge out, leaving an inconsistent fade or void next to the tread’s centered marking.
So take note of your tire tracks after driving through mud, sand or snow. If you notice uneven contact marks and faded edges from a bulging sidewall on one side, that tire likely needs more PSI.
Mass Over Wheels
Visually check if the vehicle seems to be listing, leaning or sagging more over one wheel. If the mass looks unevenly distributed, with more body sinking down on one corner, the issue may be a deflated tire on that wheel.
You can confirm by checking the relative firmness using the hands-on methods described earlier. The softer tire on the lowered corner is the likely culprit needing re-inflation. This leaning visual check is easier to perform on larger vehicles like SUVs and trucks.
Eyeball Observation
Simply observe the appearances of all four tires visually. Consistent bulge size, shape and symmetry are good signs the pressures are properly matched on all sides. Likewise, consistent tread height and contact indicates good overall inflation.
On the other hand, one tire that looks more sunken, flattened, bulged out or misshapen likely needs attention. You can follow up with the other hands-on checks to confirm which one feels softer or asymmetric.
Thumb Pressure
Similar to the palm check, you can press your thumb down into the tire sidewall, seeing how much give and flex it has. Try this various places around the side.
A tire filled to proper PSI should feel uniformly firm and resist the downward pressure without much sink-in. Whereas your thumb will likely plunge deeper into a low pressure tire with less internal air supply inside to cushion the force.
FAQS
Why Do You Need To Check Tire Pressure?
Properly inflated tires are essential for safe handling, long tread life, and good fuel economy. That’s why it’s important to check all four tires on a regular basis and keep them inflated to the PSI recommended by the vehicle manufacturer.
Under-inflated tires can create a very unsafe driving situation. Low pressure causes excessive heat buildup and uneven tread wear from improper contact with the road. This leads to blowouts and reduced traction that make controlling the vehicle difficult. Hard cornering and quick maneuvers become extremely hazardous when tires lack adequate inflation.
Not only are under-inflated tires unsafe, they also waste fuel since the engine has to work harder to overcome resistance from tire flex and deformation. The excess friction eats up gas mileage little by little. Tires that are under-filled by just 8 PSI can decrease fuel economy by over 5% from added drag.
On top of safety and fuel consumption concerns, you want to maintain proper inflation to get the full life expectancy from your tires. The excessive shoulder wear from low pressure cuts tread depth faster. Tires end up needing replacement prematurely when they aren’t kept inflated according to manufacturer guidelines.
How Often Should I Check Your Tire Pressure?
During routine vehicle upkeep, tire inflation pressure checks should occur about once per month to help ensure safety and longevity. Tires can gradually lose pressure over time from normal permeation through the rubber, and it’s wise to identify and top off any under-inflation on a regular basis.
That said, you should also check tire pressure anytime you encounter a noticeable change in handling dynamics or feel. If the steering seems to wander more than typical, you sense stuttering grip issues over bumps, the body rolls excessively on corners, braking traction has decreased, or the cabin just feels louder from external noises, begin by inspecting inflation. Unexpected changes in road feel and drive characteristics often stem from low PSI.
Likewise, check pressures again if you’ve recently hauled heavy cargo or had more than the average amount of passengers, both of which can compress tires and somewhat lower air volume. Weight drops and removal allow tire pressures to rise back up slightly. But it’s wise to periodically re-measure with a reliable gauge anytime the vehicle load changes drastically.
How do I know if my tire pressure is low?
The easiest way to know if a tire is under-inflated is to use a quality air pressure gauge and routinely check the PSI (pounds per square inch). Compare the measurements to the vehicle manufacturer’s recommended inflation level, which is usually listed on a sticker inside the driver’s side door jamb. Tires can gradually lose 1-2 PSI every month as small amounts of air permeate through the rubber, so it’s wise to periodically re-measure.
You can also identify low tire pressure through visual and performance indications without precise PSI numbers. Under-inflated tires often appear more rounded, bulge slightly, show accelerated shoulder wear on the outer tread, or have sections that look flattened on the bottom rather than flush on the pavement.
In terms of feel, low pressure tires negatively affect handling – making the steering wander, reducing grip over bumps and corners, or producing vibrations through the chassis on rough roads. Braking traction and overall ride comfort tends to diminish as well when inflation drops too far. Pay attention to changes and address any suspicious symptoms promptly.
Can I drive with low tire pressure?
It’s generally not advisable to continue driving if you notice a tire is significantly under-inflated. While you may get away with creeping home slowly or driving very short distances at low speeds if necessary, under-inflated tires create unsafe handling and risk blowouts. They should be addressed properly as soon as realistically possible.
Tires rely on adequate air pressure to maintain their shape and structural integrity under load. As inflation drops, the sidewalls and tread area flex more which builds up excessive heat. The overworked rubber is more prone to failure and cracks, increasing chances for a debilitating blowout, especially at higher speeds.
Low pressure also causes uneven tread wear patterns and reduced traction which sacrifices steering response, braking grip, and overall control authority. Hard cornering and abrupt maneuvers become dangerously unstable. The tread can shear and fly off the casing as the deformed contact patch fights for grip rather than rolling smoothly.
Likewise, the braking force needed for timely deceleration requires the tire to grip and release cleanly at minuscule intervals. Under-inflation leads to sluggish response as the tread buckles unevenly under heavy braking, extending stopping distances. This delayed grip impedes your ability to avoid obstacles or traffic conflicts at the last moment.
For all these safety related and wear concerns, you should aim to promptly re-inflate any under pressure tires before logging additional miles. The only exception might be slowly limping short distances to a filling station after detection.
