When Should You Change Your Engine Oil?

Oil is the single cheapest thing standing between your engine and a repair bill in the lakhs. Yet most owners either change it far too often, or forget about it entirely until something rattles.

The short answer

For most petrol cars in India, every 10,000 km or 12 months, whichever comes first. Diesel engines work harder and run dirtier, so aim closer to 7,000-8,000 km.

When to shorten that interval

Your driving conditions matter more than the odometer. Change it sooner if most of your driving looks like this:

• Stop-start city traffic, where the engine idles hot for long stretches
• Very short trips where the engine never fully warms up
• Dusty or unsealed roads
• Regular heavy loads, or towing

How to check it yourself

Park level, wait for the engine to cool, then pull the dipstick, wipe it, reinsert fully and pull again. You're looking at two things — the level should sit between the two marks, and the oil should be translucent amber. Gritty, or black like coffee? It's overdue.

If the oil is milky or foamy, stop and get it looked at. That usually means coolant is getting in, which is a much bigger problem than a service.

Don't skip the filter

Changing oil while keeping the old filter is a false economy — the filter holds a fair amount of dirty oil that immediately contaminates the new. Any competent workshop replaces both as a matter of course.