Conventional, synthetic blend and full synthetic oils are built from different base stocks. For a Mercedes-Benz, though, the deciding factor is the approval number on the bottle. Here is how the oils differ and how to choose the right one.
Conventional oil is made from refined crude oil. Full synthetic oil uses severely refined or chemically built base stocks, and a synthetic blend mixes the two. Those names reflect general industry usage. The American Petroleum Institute (API) does not define “synthetic,” “synthetic blend” or “conventional” as label terms. It does define five groups of base oil, which is a clearer way to see what is in the bottle.
| Base oil group | What it is | General industry usage |
|---|---|---|
| Group I and II | Conventionally refined mineral oil | Conventional oils and the mineral part of blends |
| Group III | Severely refined mineral oil | Can appear in oils labeled full synthetic |
| Group IV | Polyalphaolefin (PAO), built by chemical synthesis | Can appear in oils labeled full synthetic |
| Group V | All other base stocks, such as esters | Specialty base stocks |
Base oil groups as defined in API 1509, Annex E. “Conventional,” “blend” and “full synthetic” reflect general industry usage.
That is why the old line that synthetic oil “is not petroleum based” is misleading. Group III base stocks are severely refined mineral oil, while Group IV (PAO) and Group V stocks such as esters are made differently, so “synthetic” can describe more than one kind of base stock. No standards body sets a percentage for a “blend,” either.
The approval matters more. Mercedes-Benz does not specify oil as conventional or synthetic. It specifies an MB-Approval number, and only oils that carry that approval qualify. The Owner’s Manual puts it plainly: “Only use engine oils approved for your vehicle by Mercedes-Benz.” It also says not to use oil additives.
Mercedes-Benz publishes each approval sheet, and every oil approved against it, on its Operating Fluids site. Common sheets include 229.5, 229.51, 229.52, 229.61, 229.71 and 229.72. For context, Mercedes-Benz’s own Genuine Engine Oil for 229.51 and 229.52 is labeled fully synthetic. For a deeper answer on whether synthetic is required for every engine, see is synthetic oil required for all Mercedes-Benz engines.
Find the words “MB-Approval” followed by the sheet number your Owner’s Manual lists, for example 229.71. If you cannot find that approval on the label, check the Mercedes-Benz Operating Fluids list or ask our service team before using it. The Mercedes-Benz warranty booklet notes that improper engine oil may cause engine damage that is not covered by the warranty.
It depends on the model and engine, so always check your Owner’s Manual. Here are examples from current Mercedes-Benz manuals.
| Model examples | MB-Approval listed | Worth knowing |
|---|---|---|
| GLC 300, E-Class, GLE 350, GLE 450, S 500 | 229.71 or 229.72 | SAE 0W-20 oils |
| GLE 580 | 229.5 or 229.51 | Differs from the GLE 350 and GLE 450 |
| S 580 | 229.52 or 229.61 | Differs from the S 500 |
| GLC 350e, GLE 450e, S 580e plug-in hybrids | 229.51 or 229.52 | Differs from the gas-only version of the same model |
From the GLC (2024), E-Class (2025), GLE (2025) and S-Class (2025) Owner’s Manuals. Approvals can change by model year and engine.
Mercedes-Benz classifies 229.51, 229.52, 229.61, 229.71 and 229.72 as low SAPS oils, meaning low sulfated ash, phosphorus and sulfur. For model-by-model detail, see our Mercedes-Benz oil type guide, or browse the GLC 300, E-Class and GLE lineups at our Foothill Ranch showroom.
Mercedes-Benz schedules routine maintenance every 1 year or 10,000 miles, whichever comes first. The engine oil and filter are replaced at both Service A and Service B. Service A comes first, at approximately 10,000 miles or one year. Service B comes at approximately 20,000 miles or one year after the previous service, and the two continue to alternate.
Your vehicle’s service display tracks the schedule and reminds you when a visit is due. Your Owner’s Manual and Maintenance Booklet have the exact schedule for your model.
Both visits include Mercedes-Benz motor oil and filter replacement, and Service B adds a cabin dust filter and a brake fluid exchange. This summary is based on Mercedes-Benz USA’s published descriptions.
| Visit | When | What Mercedes-Benz USA lists |
|---|---|---|
| Service A | Approximately 10,000 miles or 1 year, then every 20,000 miles or 2 years | Mercedes-Benz motor oil and oil filter replacement, fluid level checks, tire inflation check, brake component inspection and maintenance counter reset |
| Service B | Approximately 20,000 miles or 1 year after the previous service, then every 20,000 miles or 2 years | Motor oil and filter service, plus cabin dust or combination filter replacement and a brake fluid exchange |
Exact contents vary by model. Your advisor can confirm the list for your model.
For a fuller side-by-side, read our Service A vs. Service B guide. Before you book, check the current Service A special, Service B special and oil change special. If you would rather budget ahead, ask about Mercedes-Benz Prepaid Maintenance.
Service reminder on your dash? Book your visit online in a few minutes.
Summer heat, stop-and-go traffic and dust are good reasons to use the approved oil and keep your service on time. A typical week here can mean a summer commute on the 241 toll road or the I-5, and stop-and-go traffic near the Irvine Spectrum.
If much of your driving is in heavy traffic, ask your advisor whether an earlier check makes sense for your car. Whether you drive in from Lake Forest, Trabuco Canyon or Irvine, keep an eye on your service display and book on time.
Follow the oil check steps in your Owner’s Manual, and top off only with oil carrying your engine’s MB-Approval.
Plug-in hybrids have a gasoline engine that needs approved oil, while all-electric EQ models have no gasoline engine, so they never need an engine oil change. The GLC 350e plug-in hybrid, for example, lists 229.51 or 229.52, which differs from the gas-only GLC 300.
All-electric models still have scheduled service, which focuses on filters, brake fluid, wiper blades and inspections. Our electric vehicle service guide explains what to expect, and you can browse new Mercedes-Benz electric models at our Foothill Ranch showroom.
Maintenance can be done by any qualified service outlet, although Mercedes-Benz recommends an authorized dealer. That wording comes from the Mercedes-Benz warranty booklet. Wherever you book, ask these four questions.
Keep every receipt. Mercedes-Benz’s warranty booklet treats oil changes skipped beyond the booklet intervals as a lack of proper maintenance, so records matter. Learn how to check your Mercedes-Benz warranty or service history, and if you are shopping for a Certified Pre-Owned Mercedes-Benz, ask for its service history too.
Want more ownership tips? Browse all of our service and parts tips, or see how an oil replacement service works at our Foothill Ranch service center.
Quick, straight answers to the questions owners ask most.
Have a question about your vehicle? Call our service team at 949-415-3135.
For a Mercedes-Benz, the better oil is the one carrying the MB-Approval your Owner’s Manual lists. Full synthetic oils use more highly refined or chemically built base stocks than blends, and no standard sets how much synthetic a blend must contain. The approval number is what confirms an oil is right for your engine.
Only if that exact oil carries the MB-Approval your Owner’s Manual requires. Mercedes-Benz does not specify oil by type, such as blend or synthetic. It specifies an approval number, and only oils that carry that approval qualify. If you cannot find the approval on the label, choose an approved oil instead.
The same rule applies: only an oil carrying the MB-Approval listed for your engine qualifies. Your Owner’s Manual names the approval, and Mercedes-Benz publishes approved oils on its Operating Fluids site. If a bottle does not show the approval, ask our service team before using it.
MB-Approval 229.71 is a Mercedes-Benz engine oil sheet for low SAPS 0W-20 oils. Current GLC 300, E-Class, GLE 350, GLE 450 and S 500 Owner’s Manuals list 229.71 or 229.72. An oil that meets the sheet is listed on the Mercedes-Benz Operating Fluids site.
They are separate Mercedes-Benz oil sheets used for different engines. Mercedes-Benz classifies 229.51 and 229.52 as low SAPS oils, while 229.5 is titled Multigrade Service Engine Oils and is not one of the low SAPS sheets. Because each engine is approved for specific sheets, use the one your Owner’s Manual lists rather than a neighboring number.
The Mercedes-Benz warranty booklet notes that improper engine oil may cause engine damage that is not covered by the warranty. If an oil without the right approval was used, contact our service team promptly. They can help you decide whether it should be changed.
Mercedes-Benz schedules routine maintenance every 1 year or 10,000 miles, whichever comes first, with oil and filter replacement at both Service A and Service B. Your vehicle’s service display reminds you when a visit is due, and your Maintenance Booklet has the schedule for your model.
No. Service A includes Mercedes-Benz motor oil and filter replacement plus fluid level checks, a tire inflation check, a brake component inspection and a maintenance counter reset. Service B includes the oil and filter service and adds a cabin dust filter replacement and a brake fluid exchange. Exact contents vary by model.
All-electric EQ models have no gasoline engine, so they never need an engine oil change. Their scheduled service focuses on filters, brake fluid, wiper blades and inspections. Plug-in hybrids, such as the GLC 350e, still have a gasoline engine that needs approved oil.
Mercedes-Benz of Foothill Ranch is at 81 Auto Center Drive in Foothill Ranch, a short drive from Lake Forest, Mission Viejo, Rancho Santa Margarita, Trabuco Canyon and Irvine. You can schedule online or call our service department at 949-415-3135.
Tell us your model and mileage when you book, and your advisor will review which service you are due for.
Service: 949-415-3135
Oil approvals, service intervals and service contents vary by model, model year and engine. Information reflects Mercedes-Benz USA, Mercedes-Benz Owner’s Manual and Mercedes-Benz Operating Fluids sources reviewed 09/24/2026. Always follow your Owner’s Manual, Maintenance Booklet and your vehicle’s service display.
