Most Northern California rigs share the same pattern: stored for weeks at a time, then a loaded run over Donner Pass, up Hwy 50 to the Sierra, or across hot valley pavement in summer. That pattern is hard on tires in specific, preventable ways — age, sun, underinflation, and load — and almost none of them show up as worn tread. Work through this list before a trip, not at the side of the road.
Step 1: Read the DOT date code on every tire — including the spare
On the sidewall you will find a code beginning with DOT, followed by letters and numbers. The last four digits are the birth date: the first two are the week of the year, the last two are the year. A code ending in 2419, for example, means the tire was made in the 24th week of 2019. The full code may only appear on one side of the tire, so on duals and inside-facing tires you may need a flashlight and some patience.
Write down the date for all positions, including the spare — a spare that is as old as the tires it would replace is not much of a spare. Then follow your tire and RV manufacturers' guidance on service life. The important habit is judging a tire by age plus condition, not tread alone, and replacing on age when the manufacturer says to, even if the tread still looks fine. If you bought the rig used and have no tire records, the date code is your record.
Step 2: Check pressure cold, against the right number
- Cold means cold: check before driving, not at a fuel stop after an hour on the highway. Driving heats tires and raises the reading, which can hide underinflation.
- Use the right target: your RV's certification label and owner's manual give the recommended pressure for your rig and load. The maximum pressure molded on the sidewall is a maximum, not automatically your target. When in doubt, follow the RV manufacturer's label and manual — and if you have had the rig weighed, a tire dealer can help match pressure to actual load using the tire manufacturer's load tables.
- Check every position, including inner duals and the spare. A tire that is visibly low compared with its neighbors is not a top-it-up-and-go situation until you know why it lost air.
- Underinflation is the enemy: a soft tire flexes more, builds heat, and carries load it was not set up to carry in that state. On a hot, loaded climb, that combination is how preventable failures happen.
Step 3: Look at the sidewalls and tread, up close
Get down at each tire with a flashlight, in daylight, and look slowly:
- Cracking and checking in the sidewall — fine surface cracks from age and sun are a warning to get the tire evaluated; deep cracks are a stop-and-replace conversation.
- Cuts, bulges, or bumps anywhere on the sidewall or tread. A bulge means internal damage until proven otherwise: do not drive on it.
- Uneven wear — heavy wear on one edge, feathering, or a worn patch. That pattern points at alignment, balance, axle, or pressure history, and fitting new tires without asking why repeats the wear.
- Objects in the tread — nails and screws often seal for a while and then don't. Do not pull an embedded object out at home; have a tire shop evaluate it.
- Valve stems — cracked rubber stems and missing caps are small parts that cause slow leaks. Check them every time you check pressure.
Step 4: Respect load and storage
Load: an overloaded rig or one heavy corner overloads the tires on that corner, even at correct pressure. Pack heavy items low and balanced, know that water, gear, and passengers all count, and if you have never weighed the loaded rig, a trip over a public scale is one of the cheapest pieces of information you can buy for tire — and brake and axle — health. Follow your manual's limits; they are the authority, not a guess from how the rig feels.
Storage: sun and sitting are the two slow killers here. Valley summer sun on a stored rig ages the sunny side faster, which is why tires on the same axle can look different. Tire covers for stored rigs, parking out of standing water and off bare dirt where you can, and moving the rig occasionally so it does not sit on one spot for a whole season are all simple, useful habits from most manufacturers' storage guidance. Before the first trip after storage, repeat Steps 1–3 in full — storage is exactly when age and pressure problems accumulate unnoticed.
If a tire fails on the road: the first seconds
- Grip the wheel firmly with both hands and keep the rig straight. A blowout pulls to one side; your first job is steering, not stopping.
- Do not slam the brakes. Ease off the accelerator gradually and let speed come down, braking gently only once you are slow and stable.
- Signal and work toward the shoulder or the widest safe turnout you can reach — on Hwy 49 and other narrow foothill roads, a slightly farther wide turnout is safer than a narrow shoulder inches from traffic. Our Northern California breakdown guide covers safe pull-offs, location reporting, and the mobile-tech-vs-tow decision in full.
- Once stopped: hazard lights on, everyone out on the side away from traffic if it is safe to exit, and do not attempt a tire change beside fast traffic. Changing a heavy RV tire or a trailer tire on a slope or soft shoulder is dangerous work — calling for roadside or mobile help is the normal choice, not the cautious exception.
After any tire failure, inspect the neighbors
A tire that fails can damage its partner — on a tandem-axle trailer or a dual pair, the surviving tire has just carried double load, possibly underinflated for the job, and may be damaged invisibly. Have both tires on that axle or dual position evaluated before trusting the survivor for another loaded Sierra run. Also check for collateral damage a flailing tread can cause — wheel-well, skirting, brake lines, and plumbing or wiring routed near the wheel — and mention it when you call, because that damage, not the tire, is often the repair that decides whether the trip continues.
What to tell the technician or tire shop
Have ready: the date codes and sizes from all positions, your pressure readings before the trip, how the rig is loaded, any wear pattern or damage you found in Step 3, and where the RV is parked. Our mobile RV repair page explains which work a mobile tech does at your site and which work — chassis, tires, and running gear among it — belongs with a tire or mechanical shop; a good mobile tech will tell you that plainly rather than sell you a repair that is not theirs to do.
More owner guides
- RV breakdown in Northern California — what to do on I-80, Hwy 50, and Hwy 49, from the first minutes to the tow decision.
- RV battery & converter basics — the other pre-trip check that prevents storage-lot surprises.
- RV roof inspection & reseal guide — the twice-a-year routine that prevents the most expensive water damage.
Get a mobile tech to look at it
Tell us what's happening and where the RV is parked, and we'll match you with one local mobile technician for your area — not a shared list of companies.
Disclosure: NorCal RV Repair is an independent referral service, not a repair shop. We connect RV owners in Northern California with local independent mobile RV technicians. We do not perform repairs ourselves, and pricing and warranties are provided by the independent technician who does your work. This article is general educational information about common tire-care practice, not a substitute for your RV and tire manufacturers' instructions — always follow the manuals and sidewall information for your specific rig and tires, including their service-life and pressure guidance.