Short answer
Most vehicles use one year-round multigrade oil, so you do not need to change grades each season. Instead, check the oil level and condition, the service interval, the coolant, the battery, and the other fluids before extreme weather. Choose a lower W grade only if your manufacturer allows it.
Preparing for winter
Cold starts are hard on an engine because oil is thickest before it warms up. If your manual lists more than one grade, the lower W grade (for example, 0W instead of 5W) flows faster at start-up in very cold climates.
Check the coolant’s freeze protection, test the battery, and inspect belts and hoses. In diesels, use winter-blend fuel or a cold-flow additive where appropriate to reduce gelling. A block heater helps in severe cold.
Short winter trips may never fully warm the engine, which lets moisture and fuel collect in the oil. Many manufacturers treat this as severe service with a shorter oil-change interval.
Preparing for summer
Heat, towing, heavy loads, mountain driving, and stop-and-go traffic raise oil and transmission temperatures. Check your manual’s severe-service schedule if you tow a trailer or haul regularly.
Inspect the cooling system, check the transmission fluid and differential service intervals, and make sure the air filter is clean for dusty conditions.
Seasonal equipment and storage
Before storing a boat, motorcycle, snowmobile, lawn mower, or generator, change the engine oil so acids and moisture in used oil don’t sit in the engine, and treat or drain the fuel so it doesn’t degrade. Fogging oil protects internal parts in some engines during long storage.
When you bring equipment out of storage, check the oil level, battery, fuel, and belts, and follow the manufacturer’s start-up procedure.
What not to change
Do not switch to a grade your engine does not permit, and do not extend intervals because of the season. Follow the manufacturer’s time and distance limits, whichever comes first.
Frequently asked questions
Do I need a different oil in winter?
Usually not. Most vehicles use one year-round multigrade. If your manual lists several grades, a lower W grade can help cold starts in very cold climates.
Does towing in summer affect oil changes?
Often yes. Many manufacturers classify towing and heavy loads as severe service with shorter intervals. Check your manual.
Should I change oil before storing equipment?
Yes. Changing the oil before storage keeps acids and moisture in used oil from sitting in the engine for months.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].
