How to Winterize a Classic Car: A Step-by-Step Storage Guide

Car show season winds down as the weather turns, but the work isn't over, it just moves from the show field to the garage. How you store your classic over the winter has a direct impact on how it starts, runs, and looks when show season rolls back around. Skip a step and you could be facing a dead battery, a gummed-up fuel system, or flat-spotted tires next spring.

Here's a complete walkthrough for putting your car to bed the right way.

1. Give It a Proper Wash and Wax First

Road grime, bug residue, and tree sap left on the paint over the winter can etch into the clear coat. Wash the car thoroughly, clay bar if it's been a while, and finish with a coat of wax or sealant for a protective barrier. Clean the wheel wells and undercarriage too, trapped moisture there is a common source of rust.

2. Change the Oil Before Storage, Not After

Used motor oil contains combustion byproducts and moisture that can corrode internal engine components if left sitting for months. Change the oil and filter right before storage so the engine is sitting with clean oil, not old oil, through the winter.

3. Stabilize the Fuel System

Ethanol-blended gas absorbs moisture and degrades over time, which can lead to varnish buildup in the fuel lines and carburetor. Fill the tank most of the way (this reduces condensation inside the tank), add a quality fuel stabilizer, and run the engine for 10-15 minutes so the treated fuel circulates through the entire system, not just the tank.

4. Protect the Battery

A battery left connected and unused will slowly drain and can freeze in cold temperatures once its charge drops too low. Either disconnect the battery entirely or, better, connect a smart battery tender/maintainer that keeps it topped off without overcharging all winter.

5. Deal with the Tires

Sitting in one position for months causes tires to flat-spot. A few ways to prevent it:

• Inflate tires 5-10 PSI above the normal recommended pressure to compensate for cold-weather pressure loss
• Use tire cradles or jack stands to take weight off the tires entirely, if you're storing long-term
• If neither is practical, plan to roll the car forward or backward a few feet every few weeks

6. Keep Pests Out

Mice and other rodents love a quiet, undisturbed cabin and engine bay. Steel wool stuffed into the exhaust tip and air intake (removed before starting the car again) blocks entry points. Dryer sheets or peppermint oil sachets placed around the interior are a low-effort deterrent rodents tend to avoid.

7. Protect the Interior

• Crack the windows slightly if storing in a humidity-controlled space to prevent musty odors (skip this if pests or moisture are a concern)
• Use a moisture absorber (silica gel packs or a dehumidifier bucket) inside the cabin
• Cover leather or vinyl seats to prevent cracking from temperature swings

8. Choose the Right Cover

If the car isn't in a fully enclosed, climate-controlled garage, a breathable indoor car cover prevents dust buildup without trapping moisture the way a tarp does. Avoid plastic covers, they trap condensation against the paint.

9. Check On It Periodically

Even a well-prepped car benefits from a monthly check-in: glance at tire pressure, confirm the battery tender is working, and look underneath for any signs of leaks or pest activity.

Ready for Next Season

A properly stored classic starts easier, runs cleaner, and looks better when the first shows of the season roll around. Speaking of which, start planning next season's shows now so you know exactly where you're headed once the car comes out of hibernation.