Knowing what motor oil to use is essential if you’re going to get every oil change right. We’ve made it quick and easy with our Oil Selector tool.
When it’s time for an oil change, knowing what motor oil to use is essential. The answer to that question gets more complex every day. The latest engines are getting smaller and more powerful all the time, and manufacturers are specifying complex full synthetic oils to cope with higher engine pressures and meet fuel efficiency targets.
If you’re driving a muscle car or a European import, the manufacturer may well specify a full synthetic motor oil. Alternatively if you’re driving an older domestic vehicle, the manufacturer may recommend a conventional oil. However, even though that’s the most economical option, a full synthetic will almost certainly look after your engine better. Knowing what engine oil to use at every oil change is essential.
Your owner’s manual will tell you which industry specification, type and grade of oil the manufacturer specifies, and we’ve also made it quick and easy to see all your options and make the right choice with our Oil Selector tool. Try it now.
Viscosity is a measurement of the thickness and 'ease of flow' in any liquid. For example, water is a thin liquid that flows freely, so we say that it has a low viscosity. Honey, on the other hand, is relatively thick and flows more slowly. So we describe honey as having a high viscosity. It's also worth noting that honey flows more easily - and is therefore less viscous - when it is slightly warm. Motor oil behaves in pretty much the same way, which is why mechanics will usually run an engine for a minute or two before draining used motor oil away to replace it.
What is Viscosity?
Modern day engines are smaller but more powerful than ever, operating at more than twice the internal pressure of older engines. Castrol® EDGE® is our strongest motor oil, fully synthetic and liquid engineered with Fluid Titanium Technology to make it strong enough to handle the demands of today's engines at all times.
Castrol EDGE Extended Performance with Fluid Titanium Technology provides unsurpassed protection for critical engine parts, ensuring optimal performance.
Up to 75% of engine wear takes place in the first 20 minutes after your engine starts. That's why Magnatec Stop-Start 5W-30 and C3 are liquid engineered with intelligent molecules that cling to engine components and form a protective layer from the moment you start the engine, to dramatically reduce engine wear.
Up to 75% of engine wear takes place in the first 20 minutes after your engine starts. That's why Castrol Magnatec is liquid engineered with intelligent molecules that cling to engine components and form a protective layer from the moment you start the engine, to dramatically reduce engine wear.
Sludge, varnish and carbon can build up in your engine, reducing engine life, power output and fuel economy. Castrol® GTX® ULTRACLEAN has a double-action formula that cleans away sludge and prevents new sludge from forming. It provides 45% better sludge protection than is demanded by tough industry standards.
Castrol® GTX® High Mileage Motor Oil has been liquid engineered specifically for vehicles with more than 75,000 miles on the odometer. Not only does it protect against sludge, wear and burn-off, it features Phosphorous Replacement Technology to help protect your car's emission system from catalytic converter failure.
Sludge can form in engine oilways, blocking them up to reduce power and engine life. Castrol® GTX® is a premium conventional motor oil that has been helping to extend engine life since 1968. It does so thanks to a double-action formula that cleans away old sludge and prevents new sludge from forming.
Diesel engines are designed to last for more miles and deliver better mileage along the way. But they can only do that with regular oil changes and the right diesel oil formulation. Castrol® GTX® Diesel is liquid engineered to fight sludge, protect particulate filters and preserve engine efficiency.