A car from the USA: which oil to use when the manual says ILSAC or dexos?

It is a question that everyone who has brought a car over from an American auction asks sooner or later: what goes into the engine? There is no service book, the manual is in English and says 0W-20, some kind of “starburst” and incomprehensible codes, and the shop confidently offers 5W-40 with ACEA A3/B4: European oil, they say, is “more serious”, thicker, made for our roads. There are plenty of such cars: lately roughly every fourth or fifth used passenger car brought into Ukraine has come from the USA, and alongside the electric cars there are lots of petrol Ford Escapes, Nissan Rogues and Jeep Cherokees. But “European” does not mean “better”, and thicker does not mean “more reliable”.

This is about petrol cars and hybrids; electric cars are a separate story (see the article on the fluids of an electric car).

What the American manual says

American and Japanese carmakers rely on API and ILSAC (the “International Lubricant Standardization and Approval Committee”). The “starburst” on a can means ILSAC GF-7A (0W-20, 5W-30 and so on), the “shield” means GF-7B, for 0W-16 only; more on this in the article on API SQ and ILSAC GF-7. If the manual says GF-5 or GF-6A, API itself recommends GF-7A in the viscosity the manufacturer specified.

But next to the class there is often the carmaker’s own code, and, as always, it counts for more than the class:

1. Chevrolet, GMC, Buick: dexos1. GM’s petrol specification; the current third generation (Gen 3) is backward compatible with all the earlier ones. Do not confuse it with dexos2 for older European Opels (more on that in the article on Opel after GM).

2. Ford: WSS-M2C with a number. For example, WSS-M2C960-A1 is a 5W-20 and WSS-M2C962-A1 a 0W-20. Read the code in full, suffix included: two oils of the same viscosity are not necessarily interchangeable.

3. Jeep, Dodge, Chrysler: MS- with a number. Most often it is MS-6395 (a Chrysler standard based on ILSAC), but newer turbocharged engines can call for a different one, so read the number in the manual.

4. Volkswagen, Audi, BMW. Here, as a rule, the approvals are the same as in Europe (VW 502 00 or 508 00, BMW Longlife); just check the model year by the VIN.

Where to look for the requirement if there is no service book

The first clue is the oil filler cap: Ford, for example, prints the viscosity grade on it. But it is only a clue: Ford had to replace the caps on some of its pickups and vans because they wrongly said “5W-20” instead of “5W-30”.

The more reliable way is the VIN. It is decoded free of charge by vPIC, the decoder of NHTSA, the American road-safety agency: model, model year, displacement, turbocharger, fuel and often the engine designation as well. Then you need the owner’s manual for that very model year: most manufacturers publish their American manuals online.

Can European ACEA oil replace ILSAC?

Neither API, nor ILSAC, nor ACEA publishes an official equivalence table. But the figures in the standards themselves give a few hints, and the main one is HTHS, the viscosity of the oil in the most heavily loaded parts of a hot engine (see the article on 0W-16 and 0W-8 oils).

Here are the figures side by side:

When you can: C6 (and C5) instead of 0W-20 or 5W-20

SAE requires a 0W-20 to have an HTHS of at least 2.6 mPa·s, and ACEA C5 and C6 require 2.6 to 2.9: this is exactly the band where an American 0W-20 or 5W-20 usually sits. But for a turbocharged direct-injection engine only C6 will do: unlike API SP/SQ and ILSAC, C5 has no LSPI test. One such engine is the 1.5 EcoBoost in the Escape (more on this in the article on LSPI). On ash and phosphorus the limits differ slightly, but they do not pull in opposite directions.

And some 0W-20 cans carry both ACEA C5 and API SQ with the “starburst”. An oil with both marks and the right viscosity settles the “ILSAC or ACEA” question. Look for the manufacturer’s code from the manual (dexos1, Ford WSS…) on the can as well. On the C classes, see the article on the ACEA classification.

A manual that calls for 5W-30 is another matter. For a 30 grade, SAE requires an HTHS of at least 2.9, so a C5 or C6 oil cannot be a 5W-30, and C2 (from 2.9) will do only if the manual itself names it. Otherwise, take a 5W-30 with the “starburst” and the manufacturer’s code.

When you cannot: the “thicker safety margin” of A3/B4 or C3

C3, C4 and A3/B4, on the other hand, require an HTHS of at least 3.5 mPa·s, and in practice that is a different viscosity altogether. Pouring such an oil in instead of the 0W-20 or 5W-20 from the manual means changing the viscosity in a way the manufacturer never intended. A3/B4 is also full-ash, and its phosphorus is not limited at all. An engine built for ILSAC, let alone one with a particulate filter, has no use for such a “margin”. It is like putting on winter boots for a jog “to be on the safe side”: your feet are protected, only nobody was planning to run in them.

The “European twin” of the same model

The model is sold in Europe too, so the oil must be the same as well? It varies.

Sometimes it is the same. The UK owner’s manual for the Kia Sportage (NQ5) specifies 0W-20 of API SN PLUS/SP or ILSAC GF-6 for the petrol engines, that is, “American” oil.

Sometimes it is different. As a rule, the American Escape with the 1.5 EcoBoost is designed for Ford’s North American 5W-20 specification, while the European Kuga with the same engine is designed for the European WSS-M2C948-B.

And sometimes another country allows more. The Japanese manual of the hybrid RAV4 recommends 0W-16 but, if it is not available, allows 0W-20 and even 5W-30. Toyota’s American manuals for engines built for 0W-16 are stricter: 0W-20 is only a stopgap until the next oil change.

So what decides is the market your particular car was built for, in other words its VIN. What the manufacturer allowed owners in another country does not apply to your engine.

10,000 miles and Ukrainian roads

American intervals look generous. From the 2010 model year Toyota gradually moved to 10,000 miles (about 16,000 km) for most cars that require 0W-20. Ford, as a rule, gives up to a year or 10,000 miles, whichever comes first. GM says the oil must be changed at least once a year, whatever the Oil Life system shows.

Then again, Toyota in Britain services the hybrid RAV4 in just the same way: once a year or every 10,000 miles. So it is the conditions that decide. In a bulletin for its American dealers, the same Toyota says it plainly: under “special operating conditions” (dirt roads, towing, repeated short trips in freezing weather, long idling) the oil must be changed every 5,000 miles (about 8,000 km), whatever oil is in the engine. Sound familiar? For many cars in Ukraine such “special” conditions are an everyday thing. More on this in the article on the oil change interval today.

What should the owner of an “American” do?

1. Identify the engine by the VIN and find its American owner’s manual for that model year.

2. Buy the viscosity and the code: an oil with the GF-7A “starburst” (for 0W-16, with the GF-7B “shield”) and with the manufacturer’s code if the manual gives one (dexos1, Ford WSS-M2C…, MS-…). GF-6 oils lost the “starburst” and the “shield” on 1 October 2026, although they will stay on the shelves for a long time yet.

3. ACEA only as an exact counterpart: C6 instead of 0W-20 or 5W-20 (C5 only for an engine without a turbo), C7 instead of 0W-16; for 5W-30 there is no counterpart, so take the “starburst”. Do not pour in A3/B4, C3 or 5W-40 “to be on the safe side” instead of 0W-20.

4. Count the interval by the special-conditions column: for town driving, short distances and winter, think 8,000 km rather than 16,000, and no less often than once a year.

I will say it yet again: a car from the USA is not an exception to the rule but a confirmation of it: the oil is chosen by the manufacturer of your car, and for the very market the car was built for. The best oil is the one that matches the manual.