Search Suggestions
Categories
Products
View All Results
At Opie Oils, we know how important it is to keep your engine oil doing its job properly, free from harmful sludge build-up. Castrol GTX is a trusted anti-sludge engine oil for petrol and diesel engines, using a double-action formula that clears existing deposits and helps prevent new ones from forming. Whether your vehicle calls for 5W-30, 10W-40, 15W-40 or 20W-50, we stock the full Castrol GTX range to keep your engine running cleanly for longer. Shop the full range below.
Filter Results
8 Products
Castrol GTX has been a mainstay on UK forecourts for decades, and it remains one of the most trusted names in mineral,semi-synthetic and full synthetic engine oil. Its Double-Action formula is built to clear existing sludge from your engine's oilways and stop new deposits forming, helping to protect against wear, reduce oil consumption, and extend engine life – particularly useful for older or higher-mileage vehicles.
There is a GTX oil for most cars on the road. There are the 0w-16 and 0w-20 variants for the latest hybrid engines, various 5w-30s to cover ACEA C2, C3 and C4 as well as the more traditional 10w-40 and 15w-40 for older vehicles.
Not sure which grade or specification is right for your vehicle? Use our parts finder to check the correct oil for your registration, or get in touch – our team of friendly experts are always here to help with recommendations and advice. For more background, our guide to engine oil viscosity and grades explains what those numbers actually mean, while our ACEA specifications explained guide covers what C3 and C4 mean for your engine.
As the UK's largest independent supplier of automotive oils, fluids and parts, we carry the full range of Castrol GTX grades, including some of the harder-to-find specifications, backed by more than 10,000 genuine 5-star reviews on reviews.io. Unlike most retailers, we offer free expert advice from a real team who can talk you through the right oil for your engine, and every order is covered by our 60-day returns policy for extra peace of mind.
It depends on the grade. 0w-16, 0w-20 and 5w-30 are synthetics, 10w-40 is a semi-synthetic and 15w-40 is a mineral oil. Whichever you choose, all Castrol GTX oils use the same Double-Action formula to fight sludge.
Yes. Several Castrol GTX oils, including the C3 and C4 variants, are formulated for both petrol and diesel engines and meet the relevant ACEA diesel specifications, so always check your handbook for the exact approval you need.
This varies by vehicle, so always follow your manufacturer's recommended service interval. If you're unsure, our team can help you check the correct interval and oil quantity for your car.
Shop the full Castrol GTX range at Opie Oils today, with free UK delivery on orders over £80 (geographic restrictions apply) and our no-leak guarantee on every order.
