FAQs

The one that matches both the viscosity grade and the specification your vehicle's manufacturer sets. The grade, such as 5W-30, describes how the oil flows. The specification, such as API SP, ACEA C3 or a carmaker's own standard, sets how it performs. Both are in your handbook.

Every Duckhams product page lists the oil's grade and the specifications it meets, so you can match them, and our partner can help you choose.

They're SAE viscosity grades, which describe how thick the oil is at different temperatures. The first number shows how easily the oil flows from cold: the lower it is, the faster oil reaches the engine at start-up. The second number shows how thick the oil stays at running temperature: the higher it is, the thicker the oil.

So 5W-30 flows more easily from cold than 10W-40, and 5W-40 stays thicker when hot than 5W-30.

The W stands for winter, not weight, which is a common mix-up. The number before it shows how well the oil flows in cold conditions. A 5W oil flows more easily from a cold start than a 10W or 15W oil. That matters because much of an engine's wear happens in the first moments after start-up, before the oil has fully circulated.

Oils of the same grade and specification can be mixed, so topping up with a different brand is fine if you need to. Avoid mixing different grades or specifications, as the mix may no longer meet the specification your engine needs. Where you can, top up with the same oil that's already in the engine. If you've had to mix, go back to the correct oil at your next change.

Fully synthetic oil is made from highly refined or chemically engineered base oils. It stays stable at high temperatures, flows well from cold and lasts longer between changes, so it suits most modern engines and long-life service intervals.

Semi-synthetic oil blends synthetic and mineral base oils for a balance of performance and price. Mineral oil is refined from crude oil and suits many older and classic engines.

Your manufacturer's grade and specification will usually point you to the right type.

It can, though rarely straight away. A one-off top-up with the wrong grade is unlikely to cause harm, but replace it at your next opportunity. Over time, the wrong oil can increase wear, reduce protection at start-up and, on vehicles with a diesel or petrol particulate filter (DPF or GPF), cause the filter to clog.

If you've added a different fluid altogether, such as gearbox oil or coolant, don't drive the vehicle. Get advice from a garage.

No. The best oil for your vehicle is the one that meets your manufacturer's grade and specification, whatever it costs. A premium oil that doesn't meet the required specification won't protect your engine better, and on modern engines with a particulate filter it can cause harm. A higher price often reflects a more demanding specification or a better base oil, which only matters if your engine needs it.

Yes, in most cases, as long as the synthetic oil meets the grade and specification your manufacturer sets. Mineral and synthetic oils are compatible, so you don't need a special flush. The idea that synthetic oil causes leaks in older engines dates from early formulations; modern oils don't damage seals.

On a high-mileage engine with worn seals, though, a synthetic oil can show up leaks that were already there, so check the oil level more often after switching.

A small overfill, just above the maximum mark, is unlikely to cause harm, but more than that can. Too much oil can be whipped into foam by the crankshaft, which reduces lubrication and can force oil past seals. Some engines may also burn the excess, damaging the catalytic converter or particulate filter.

If the level is well above the maximum mark, have the excess drained before driving any distance.

Viscosity (the grade, such as 5W-30) only tells you how thick the oil is. The specification tells you what the oil can do: how well it controls wear, deposits and sludge, how long it lasts, and whether it's safe for your exhaust after-treatment. Two 5W-30 oils can perform very differently.

An oil with the right grade but the wrong specification can still wear your engine faster or clog a particulate filter. Your vehicle needs both to match.

An approval means the vehicle manufacturer has tested the oil and formally listed it against its own standard, such as VW 504 00 or MB-Approval 229.51. A recommendation, often worded as “meets” or “suitable for”, means the oil maker states the oil meets that standard's requirements, without the manufacturer's formal listing.

If your vehicle is under warranty, check your handbook: some manufacturers ask specifically for an approved oil.

Every Duckhams product page lists the oil's grade and the specifications it meets. For full technical detail, download the product data sheet from the product page. For a safety data sheet, contact us through the Contact page.

SAPS stands for sulphated ash, phosphorus and sulphur. These come from additives that protect the engine, but over time they can clog diesel and petrol particulate filters (DPF and GPF) and reduce how well catalytic converters work.

Low-SAPS and mid-SAPS oils limit these additives to protect your exhaust after-treatment while still protecting the engine. Most modern cars with a particulate filter need one, usually an ACEA C-category oil.

OEM stands for original equipment manufacturer, meaning the vehicle maker. An OEM approval is a carmaker's own oil standard, set for its engines and often stricter than ACEA or API. Common examples include VW 504 00 and 507 00, BMW Longlife-04, MB-Approval 229.51, Ford WSS-M2C913-D and Renault RN0720.

If your handbook names an OEM approval, choose an oil that lists that exact code.

Modern engines are smaller, more highly turbocharged and built to meet strict emissions limits. They run hotter, use particulate filters and catalysts that certain additives can damage, and often have longer service intervals.

Many are also designed for thinner oils, such as 0W-20, to cut fuel use, and some use timing belts that run in oil. Each of these puts different demands on the oil, which is why manufacturers set precise standards for their engines.

Yes. Many oils meet several standards at once, such as ACEA C3 alongside VW 504 00/507 00, BMW Longlife-04 and MB-Approval 229.51, which is why a single oil can suit vehicles from several brands. Some standards can't be combined, though. A full-SAPS oil can't also meet a low-SAPS standard, for example. Always check that your vehicle's exact specification appears on the label or product page.

ACEA C oils are designed for vehicles with exhaust after-treatment, such as diesel and petrol particulate filters. They have limited levels of SAPS to protect these systems, so they're often called low-SAPS or mid-SAPS oils.

The categories currently run from C2 to C7. They differ mainly in SAPS level and in high-temperature viscosity, which affects fuel economy. C3 is the most widely used. The numbers aren't a ranking, so use the exact category your manufacturer specifies.

Follow the service schedule in your vehicle's handbook. It gives a distance and a time, and the oil should be changed at whichever comes first. Heat, dust, heavy traffic and short journeys are hard on oil, and most handbooks ask for shorter intervals when a vehicle is used that way. Change the oil filter at the same time.

Yes. Change the oil filter at every oil change. The old filter holds dirt, metal particles and used oil, which would contaminate fresh oil straight away. A clogged filter can also open its bypass valve, sending unfiltered oil around the engine. Always fit the filter specified for your engine.

Yes, as long as the Duckhams oil meets the same grade and specification as the oil already in your engine. Engine oils that share a grade and specification are compatible, whatever the brand. Add a little at a time, check the dipstick as you go, and don't fill past the maximum mark. Keeping a bottle of the right oil in the car makes topping up easy.

Yes. On short journeys the engine doesn't reach full operating temperature, so moisture and unburnt fuel build up in the oil instead of burning off. This dilutes the oil, uses up its additives faster and can form sludge. On diesels, short trips can also interrupt particulate filter regeneration, which can add fuel to the oil.

If most of your driving is short journeys, follow the Severe service schedule and change your oil more often.

No, not unless your manufacturer lists a thicker grade for hot conditions. Your engine's cooling system keeps the oil at a steady working temperature, so the weather has much less effect than you might think. A thicker oil than specified flows more slowly at start-up and can reduce efficiency. Some handbooks list an alternative grade for very hot climates or heavy towing; only use one if it's listed.

Yes. Alongside engine oils for cars and commercial vehicles, the range in the UAE includes D-Matic transmission fluids, Hypoid S gear oils, Galrex industrial gear oils, Zircon hydraulic oils, Trans HD heavy-duty transmission oils, Long Life Coolant and brake and clutch fluid. Each has its own page in our products.

Check it at least once a month and before any long journey. Check more often if your vehicle is older, has high mileage or has used oil before. Most engines use a little oil between services, so a gradual drop is normal, but a sudden one isn't. Our Advice page has a step-by-step guide to checking it.

Colour alone isn't a reliable guide. Diesel oil turns black soon after a change, so go by your service schedule.

It can. As oil ages, its additives wear out and contaminants build up, which increases friction inside the engine. The engine then has to work harder, using slightly more fuel. The effect is usually small, but it adds up, particularly in modern engines designed for thinner, fuel-saving oils such as 0W-20. Changing your oil on schedule, with the specified grade, keeps your engine running as efficiently as it was designed to.

If the red oil pressure light comes on while you're driving, pull over as soon as it's safe and switch off the engine. Low oil pressure can seriously damage an engine within minutes. Wait a few minutes, check the oil level and top up if it's low. If the light stays on with the level correct, don't drive on; call a garage or breakdown service.

An amber or yellow oil light usually means the level is low or a service is due. Check the level and top up soon. Your handbook explains your vehicle's warning lights.

Yes. Duckhams is official oil partner to West Surrey Racing (WSR) in the British Touring Car Championship (BTCC) and sponsors Duckhams Yuasa Racing in the Porsche Carrera Cup GB. Racing puts oil under extreme heat and load, and what we learn there informs the development of our road car oils.

Performance oils are usually fully synthetic and formulated to protect engines at high temperatures and high revs. They resist thinning under heat and shear, keep a stronger oil film between moving parts, and evaporate less, so the engine uses less oil. They're designed for high-performance and turbocharged engines, and for drivers who regularly push their car hard.

Yes, if it meets your car's grade and specification. Performance road oils are designed for everyday use as well as spirited driving. Race-only oils are different: they often don't meet road car specifications, may not be compatible with particulate filters and are designed for short change intervals. Don't use a race-only oil on the road.

Racing engines run at very high revs and temperatures for long periods, and cornering forces throw oil away from the oil pickup. The oil has to keep protecting moving parts, carry heat away and resist breaking down throughout. If it fails, the engine can be damaged in seconds and the race is over. Gearbox and brake fluids face similar extremes.

Often, yes. Racing oils are tailored to a specific engine and championship, and may be thinner or thicker than road oils depending on the engine design. They're built for maximum protection and performance over a short life, usually being changed after each race or event. They don't need to meet road car specifications for long service intervals or exhaust after-treatment.

Yes. Track driving counts as severe use: sustained high revs and temperatures break the oil down much faster than road driving. If you take your car on track regularly, change the oil more often than the standard interval, for example after every few track days, and check the level before and between sessions. Some drivers change it after every track day.

Yes. At high revs and temperatures, more oil evaporates, more gets past the piston rings and more is burned. Hard driving also raises pressure inside the engine, which can push oil vapour through the breather system. Check your oil level before and after a spirited drive or track day, and top up with the correct oil when needed.

No. Duckhams products are sold through our partner rather than directly by Duckhams. Our Where to Buy page gives their contact details.

In the UAE, Duckhams oils are distributed by our partner, Emirates for Universal Tyres LLC. Our Where to Buy page gives their contact details and lists workshops that use Duckhams oils in the UAE, Oman, Qatar and Kuwait.

Our Where to Buy page lists workshops in the UAE, Oman, Qatar and Kuwait. Search by name or area, or choose a country and city, then tap Call to see the workshop's number.

Contact our trade team through the Distributor & Trade enquiry form. Tell us your company name, location, the type of business you run and the products you're interested in, and the right person will be in touch.

Our technical team can help. Contact us through the Technical & Product Support enquiry form on our Contact page with the product name and your question. If it's about a particular vehicle, include its make, model, engine and year.

Yes. A product data sheet (PDS) is available for every Duckhams product. Download them from the product page or contact us if you need a sheet that isn't listed.

Yes. Duckhams supplies oils and fluids for cars, vans and light commercial vehicles, in pack sizes suited to fleet maintenance. Our team can help you choose the right products across a mixed fleet. Contact us through the Distributor & Trade enquiry form with the number and types of vehicles you run.

Through our partner in the UAE, Emirates for Universal Tyres LLC, whose details are on our Where to Buy page. To become a Duckhams distributor yourself, use the Distributor & Trade enquiry form on our Contact page.

For distribution, partnerships, sponsorship or other commercial enquiries, contact us through our Contact page and choose the enquiry type that fits, such as Distributor & Trade or Motorsport & Partnerships. Include a short summary of the opportunity and your contact details, and we'll pass it to the right team.