An Often Overlooked Vehicle Maintenance Item
A healthy spare tire is crucial to have during a road side emergency when a punctured or damaged tire makes the vehicle unsafe to drive. However, the spare tire’s inflation pressure, tread depth, and sidewall condition are often overlooked during routine vehicle inspections. The spare might be unsafe and unusable when you need it the most. Surprisingly, some vehicles are not equipped with a spare tire at all. It’s responsible to understand spare tire alternatives or to have the health of your spare tire inspected regularly to ensure you won’t be left stranded during a road side emergency.
I Inspected Hundreds, possibly Thousands of Vehicles
I’m an automotive service technician by trade. In 2019 I was awarded the Ford Master Technician certification in chassis, gasoline, and diesel diagnoses and repairs. Most of my career experience is with the Ford brand; however, as a licensed tech, I often worked on any brand of car, truck, or minivan.
I performed a basic visual inspection on just about every vehicle I ever worked on professionally. The inspection report is the bread and butter (pardon the cliché) of an automotive repair facility. It’s a tool used to identify, assess, and recommend additional servicing or repairs to customers.
The spare tire’s health was a safety item I overlooked for many years working as an automotive service tech. It wasn’t until a dispatched work order explicitly requesting to have the vehicle’s spare tire inspected that I realized basic visual inspections neglect the health of the spare tire.
What’s Inspected during an Inspection?
The spare tire’s pressure is generally not inspected during routine vehicle maintenance, such as when the engine oil and filter are changed. Techs will often perform a complimentary basic visual inspection of the exterior lights, under-hood components, steering & suspension, brakes, and tires — but not the spare tire.
Spare tire inflation pressure, tread depth, and sidewall health tend to only be assessed during a used-vehicle inspection, an inspection performed by a licensed tech before a trade-in or pre-owned vehicle is eligible to sell at a dealership.
You may have to practice consumer prudence to ensure your vehicle is about to receive a quality inspection when it goes into a shop. An ideal practice is to review a blank copy of a service facility’s complimentary inspection report form before dropping off your vehicle to familiarize yourself with the depth of the inspection. You may want to consider paying for a comprehensive inspection, if the complimentary one isn’t satisfactory.
If the cost of a comprehensive, multi-point inspection is objectionable, you may specifically request on the work order to have the spare tire’s condition solely inspected.
Check It Yourself
Always wear the appropriate personal protective equipment for the situation.
You can inspect your vehicle’s spare tire. If you don’t know where it’s located on your vehicle, refer to your owner’s manual. If you have lost or misplaced your owner’s manual, a quick online search may be fruitful.
Verify that you have safe access your vehicle’s spare before performing an inspection yourself.
The spare tire inflation pressure specification is usually stamped on the sidewall of the tire. Before checking the inflation pressure, locate and inspect the valve stem. It may be cracked, stressed, or leaking. If the stem is okay, apply a pressure gauge to read the tire’s pressure.
If the inflation pressure is too low, use compressed air and an air chuck to re-inflate your spare to the correct pressure. If the inflation pressure is too high, use a suitable tool to depress the valve core to release some pressure.
Low inflation pressure may indicate that your spare tire has a slow leak. It may need to be repaired.
After you have ensured that the spare tire is inflated to specification, you will want to do a visual inspection of the tread depth and sidewalls. Tire treads tend to have wear bars or wear indicators. They are found between the main grooves of the tire’s tread. If the main groove’s height is equal to the wear bar’s height, your spare tire will need to be replaced.
If the inflation pressure is set and the tread depth is okay, give the sidewalls of the spare tire a visual inspection. Ensure there are no cracks, grooves, or gouges that could cause the sidewall to split or burst under stress.
Lastly, it’s good practice to consider the integrity of the spare tire’s rim. Have a look for cracks, bends, or excessive rust. Any of which may indicate that you need to replace the rim.
If there is something you observed that you are unsure about, have a licensed automotive tech inspect it. An aspect of your spare tire may need to be repaired or replaced.
Spare tires may become interchanged with another vehicle for a variety of reasons. So when inspecting your own spare tire, verify that it’s the correct size and rating for your vehicle. Refer to the owner’s manual if you are unsure.
Running mismatched tire sizes may damage your vehicle’s differential, transfer case, or transmission. Your spare tire might not be the same size or offset, if your vehicle is equipped with aftermarket rims and tires. Ensure that your spare matches the aftermarket tire size.
Always refer to your owner’s manual for your vehicle’s specifications. If your aren’t confident or are unsure, contact an automotive repair facility or tire shop for assurance.
Your Vehicle May Not Be Equipped with a Spare Tire
Some vehicles are not equipped with a spare tire. So it’s responsible practice to know what to do in the event your vehicle picks up a flat tire.
It’s possible that your vehicle is equipped with an aerosol can of tire sealant to temporarily repair a flat tire. The sealant is injected through the tire’s valve stem to seal the puncture or leak. This temporary tire repair option often relies on a 12V portable air compressor to re-inflate a leaky tire.
Always refer to the instructions when using tire sealants or portable air compressors.
Another possibility is that your vehicle has run-flat tires installed. A run-flat tire relies on its reinforced sidewall when inflation pressure is low or zero. Run-flat tires may allow you to drive at a reduced speed to a repair facility or tire shop. Tire health and longevity are greatly reduced when relying too heavily on a tire’s run-flat technology.
Your vehicle may be missing its spare tire altogether. So if your owner’s manual says there’s storage somewhere on your vehicle for a spare tire and a spare isn’t there, you will need to procure a new spare tire.
The Take-away
If your vehicle is not equipped with a spare tire, it is responsible to understand the limitations of run-flat tires or aerosol tire sealant to temporarily seal a leak.
The spare tire is often overlooked, but a spare tire becomes a lifesaver when you’re stranded on the side of the road with flat tire. Checking the condition and health of your vehicle’s spare tire or having a licensed automotive service technician inspect it for you is responsible driver practice.
Always refer to your vehicle’s owner’s manual for specifications and instructions before undertaking any vehicle maintenance or servicing.
