Motor Oil Guide 2025: The Right Oil for Your Vehicle

The right motor oil is crucial for the lifespan and performance of your engine. But with so many designations like 5W-30, 5W-40, or 0W-20, choosing can be confusing. In this guide, we explain everything you need to know about motor oil – from viscosity to optimal change intervals.

Motor Oil Types Overview

Mineral Oil

The classic motor oil from crude oil:

Synthetic Oil (Fully Synthetic)

High quality and long-lasting:

Semi-Synthetic Oil

The compromise:

Comparison: Mineral vs. Synthetic

Understanding Viscosity: What Does 5W-30 Mean?

Viscosity describes the flow properties of oil at different temperatures.

The SAE Classification Explained

A designation like 5W-30 means:

Common Viscosity Classes

Manufacturer Approvals and Standards

Important Approvals

In addition to viscosity, manufacturer approvals are crucial:

ACEA Classification

The European standard for motor oils:

Buy Motor Oil Online

When to Change Motor Oil?

Change Intervals

Intervals vary depending on the vehicle and oil type:

Signs of Due Oil Change

Watch for these warning signals:

• 🔴 Oil warning light illuminates
• ⬛ Very dark oil on the dipstick
• 📉 Oil level drops significantly between services
• 🔊 Louder engine noises than usual
• 📅 Service interval reached according to onboard computer

Motor Oil Price Overview 2025

Change Motor Oil Yourself?

Pros and Cons

Required Materials for DIY

If you want to change it yourself:

1. Motor oil in the correct quantity and specification
2. Oil filter matching your vehicle
3. Drain plug gasket (new)
4. Oil catch pan (at least 6-liter capacity)
5. Ratchet and socket for drain plug
6. Oil filter wrench (depending on filter type)
7. Gloves and rags
8. Funnel for filling

Popular Motor Oil Brands

Frequently Asked Questions (FAQ)

Can I mix different motor oils?

In principle yes, if both oils have the same specification. However, this should only be done in emergencies. Replace completely at the next regular change.

How much oil does my car need?

Most passenger cars require 4-6 liters. The exact amount is in the owner's manual. When changing, always fill in slightly less and then check with the dipstick.

Is expensive oil really better?

Not necessarily. More important is that the oil has the correct specification and manufacturer approval. A cheaper oil with the correct approval is better than an expensive one without.

What does "longlife oil" mean?

Longlife oils are high-quality synthetic oils developed for extended change intervals (up to 30,000 km). They require special approvals and are more expensive.

Can I switch from mineral oil to synthetic oil?

Yes, this is possible without problems and even recommended. However, not the other way around – after synthetic oil, you should not switch back to mineral oil.

Checklist: Motor Oil Purchase

Use this checklist:

1. ✅ Check viscosity in service book/owner's manual
2. ✅ Determine manufacturer approval(s)
3. ✅ Consider ACEA class (especially with DPF)
4. ✅ Determine required oil quantity (+ 0.5L reserve)
5. ✅ Don't forget the oil filter
6. ✅ Buy drain plug gasket too
7. ✅ Compare prices (5L container cheaper)
8. ✅ Plan disposal of used oil

Conclusion

The right motor oil is essential for your engine's lifespan. Always pay attention to the viscosity and approvals specified by the manufacturer. Synthetic oils offer better protection and longer change intervals but are more expensive. A price comparison when buying online can be worthwhile.

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Last updated: November 2025. All information is general guidance and may change. For vehicle-specific requirements, consult the owner's manual or a qualified workshop. This guide is for informational purposes only.