07/01/2012
Owning a high-performance hot hatch like the BMW M135i is an absolute joy, blending exhilarating power with everyday usability. However, keeping these sophisticated machines in top condition requires regular maintenance, and one of the most common queries among owners revolves around the cost of an oil and filter service. While crucial for the longevity and performance of your M135i's engine, the pricing can vary significantly depending on where you choose to have the work done and what exactly is included.
Many M135i owners, especially those new to the BMW brand or high-performance vehicles, often find themselves surprised by main dealer service quotes. For a standard oil and filter service, along with a 'Vehicle Check', a BMW main dealer might quote in the region of £450. This figure, while seemingly steep to some, typically covers the cost of genuine BMW parts, specialist labour rates, and the peace of mind that comes with a manufacturer-approved service history. However, it's vital to understand precisely what this £450 encompasses, as it often *doesn't* include other wear-and-tear items that might be due soon after, such as brake fluid changes or new brake pads.
Understanding the Main Dealer Service Quote
When a BMW main dealer quotes £450 for an M135i service, it generally includes:
- Engine Oil Change: Draining the old oil and refilling with BMW-approved synthetic oil.
- Oil Filter Replacement: Installing a new, genuine BMW oil filter.
- Vehicle Check: A multi-point inspection of various components, including lights, tyres, brakes (visual inspection), fluid levels, and often a fault code read from the car's diagnostic system. This is more of a health check than an in-depth repair service.
What's often *not* included in this specific quote, but will likely be due at similar intervals or shortly after, are items like:
- Brake fluid change (typically every two years).
- Brake pad replacement (front and/or rear, depending on wear).
- Other filters (e.g., air filter, cabin filter) – these are usually part of a larger 'Inspection 1' or 'Inspection 2' service, not a basic oil service.
- Spark plug replacement.
Therefore, while £450 might seem high for just an oil change, it's the tip of the iceberg for overall running costs, especially if your car is approaching higher mileage or age points where more comprehensive maintenance is required.
Alternative Service Options: Saving Your Pennies
For many M135i owners, the main dealer price point can be a significant deterrent. Fortunately, there are viable alternatives that can substantially reduce your servicing costs without compromising on quality, provided you choose wisely.
Independent BMW Specialists
Independent garages that specialise in BMWs often offer a fantastic middle ground. They possess the necessary diagnostic tools, expertise, and often use genuine or OEM (Original Equipment Manufacturer) equivalent parts, but their labour rates are typically lower than main dealerships. For an M135i oil and filter service, you might expect to pay anywhere from £250 to £350 at a reputable independent specialist. This offers a significant saving compared to the main dealer, while still ensuring the work is carried out by experienced professionals.
DIY Servicing: For the Enthusiast
If you're mechanically inclined and have the right tools, performing an oil and filter change yourself can be the most cost-effective option. The cost of materials – oil and an oil filter – typically ranges from £50 to £100. This is a substantial saving, potentially bringing the total cost down to just over a tenth of the main dealer's quote. However, it requires a good understanding of the process, safe working practices, and the willingness to get your hands dirty. Moreover, you'll need to source the correct oil specifications (more on this later) and ensure proper disposal of the used oil.
| Service Type | Estimated Cost (UK) | Pros | Cons |
|---|---|---|---|
| BMW Main Dealer | £450+ | Genuine parts, manufacturer-approved service history, latest diagnostics. | Highest cost, potentially less flexible. |
| Independent BMW Specialist | £250 - £350 | Significant savings, specialist knowledge, often more personal service. | Varies by garage reputation, may not use all genuine BMW parts unless requested. |
| DIY (Parts Only) | £50 - £100 | Maximum savings, full control over parts used, satisfying. | Requires tools, technical knowledge, proper disposal, no service stamp. |
The BMW B58 Engine: Oil System Specifics
The M135i, particularly the F20/F21 generation, often features the excellent B58 engine (though some earlier models had the N55). This engine is renowned for its blend of power and efficiency, but it has some unique characteristics when it comes to oil maintenance that owners should be aware of:
No Dipstick!
One of the most surprising facts for new BMW owners, especially those coming from other brands, is that modern BMWs, including the M135i's B58 engine, do not have a physical dipstick for checking the oil level. Instead, the oil level is measured electronically via the iDrive system. This can be a bit disconcerting initially, but the system is generally accurate. To check the oil, you typically need to navigate through the iDrive menu (often under 'Vehicle Status' or 'Service') and initiate an oil level measurement, which usually requires the engine to be at operating temperature after a short drive.
Oil Capacity and Refill
The theoretical oil capacity for the B58 engine is around 6.5 litres. However, in practice, even after a thorough drain, you might find that you can only get about 6 litres back in before it registers as full on the iDrive system. A common recommendation is to initially add around 5.5 litres, then run the oil volume check, and top up incrementally if needed. This prevents overfilling, which can be detrimental to the engine.
Recommended Oil Grades for Your B58
Selecting the correct oil grade is paramount for the health of your M135i's engine. BMW specifies oils that meet their 'Longlife' specifications (e.g., LL-01, LL-04, LL-12FE, LL-17FE+), which ensure the oil can withstand the high temperatures and stresses of modern engines. Beyond these specifications, the viscosity (e.g., 0w30, 5w30, 5w40) can be adjusted based on mileage and usage:
- For B58 engines with less than 30,000 miles: 0w30 is often recommended for year-round use, offering excellent cold-start protection and fuel efficiency.
- For engines after 30,000 miles (especially if driven hard or with unknown history): Considering a 5w30 for winter use might be beneficial.
- For engines exceeding 50,000-60,000 miles: A 5w30 oil year-round is a common choice, providing a slightly thicker film at operating temperature.
- For engines over 100,000 miles: Some owners opt for a 5w40 to provide even greater protection at higher temperatures, especially if the engine shows any signs of oil consumption.
Always consult your owner's manual for the precise BMW Longlife specification required for your specific M135i model year and region.
Aftermarket Oil Filter Housing
A small but impactful upgrade for DIYers or independent garages is replacing the standard plastic oil filter housing with an aluminium aftermarket one. Brands like BMS (Burger Motorsport) offer these for around £90. The key benefit is durability and ease of removal – the plastic housings can become brittle and difficult to remove without damage over time, whereas the aluminium version is much more robust.
M135i vs. M2/Cayman: A Running Cost Reality Check
Some M135i owners might consider upgrading to vehicles like the BMW M2 or a Porsche Cayman, believing they might be cheaper to run, perhaps due to service plans. However, it's crucial to compare apples with apples. While a service plan might reduce the *per-service* cost, the overall running costs of an M2 or a Cayman are almost certainly higher than an M135i, for several reasons:
- Fuel Consumption: The B58 engine in the M135i is remarkably efficient for its performance. An M2, for instance, often delivers around 5mpg worse fuel consumption. Over 10,000-12,000 miles annually, this difference alone can easily outweigh any perceived service plan savings.
- Tax & Insurance: Higher performance cars typically fall into higher insurance groups and may incur greater Vehicle Excise Duty (VED).
- Consumables: Tyres and brakes for M2s and Caymans are often larger, more specialised, and significantly more expensive than those for an M135i. This is a major factor in long-term running costs.
While an M2 or Cayman might offer a different driving experience or prestige, it takes a lot of "man maths" to argue they're cheaper to run than a well-maintained M135i.
Maximising Value and Longevity for Your M135i
To keep your M135i running optimally and to manage long-term costs effectively, consider these tips:
- Adhere to Service Intervals: Whether you choose a main dealer or an independent, stick to BMW's recommended service intervals. Regular oil changes are the single most important maintenance item for engine longevity.
- Use Correct Fluids: Always use engine oil that meets BMW's 'Longlife' specifications. Don't be tempted by cheaper, unapproved alternatives.
- Proactive Maintenance: Address minor issues before they become major problems. Listen to your car, and don't ignore dashboard warnings.
- Keep Records: Maintain a comprehensive service history. This not only helps you track maintenance but also adds significant value if you decide to sell the car.
- Consider a Service Plan (Carefully): If buying new, a service plan can budget costs effectively, but always calculate if the overall cost offers a genuine saving compared to independent servicing. For used cars, they are less common but worth exploring if available.
Frequently Asked Questions (FAQs)
How often should I service my M135i?
BMW's Condition Based Servicing (CBS) system determines service intervals based on driving style and mileage. Typically, an oil service is due every 18,000-20,000 miles or every two years, whichever comes first. However, many enthusiasts prefer to change the oil more frequently, perhaps annually or every 10,000 miles, especially if the car is driven hard.
Can I use non-BMW approved oil?
While you can use oil from reputable brands, it *must* meet the specific BMW 'Longlife' specification for your engine (e.g., LL-01, LL-04, LL-17FE+). Using oil that doesn't meet these standards can void warranties and potentially cause engine damage.
Where is the dipstick on my M135i?
Your M135i (with the B58 engine) does not have a traditional physical dipstick. The oil level is checked electronically via the iDrive system in the car's infotainment display.
What oil weight should I use for my M135i?
For B58 engines, 0w30 is often recommended for newer, lower mileage cars. As mileage increases (e.g., over 50k miles), 5w30 or even 5w40 (for very high mileage or hard use) may be considered, always ensuring it meets the required BMW Longlife specification.
Is a service plan worth it for a used M135i?
For used cars, service plans are less common. If offered, compare the total cost of the plan against estimated costs for independent servicing over the same period. Often, for older cars, independent specialists offer better value.
What does a 'Vehicle Check' include?
A BMW 'Vehicle Check' is a multi-point visual inspection of key components like tyres, brakes, lights, fluid levels, and a diagnostic scan for fault codes. It's a general health check rather than a hands-on repair or replacement service.
Ultimately, keeping your M135i running beautifully doesn't have to break the bank. By understanding the costs, exploring your options, and making informed decisions about maintenance, you can enjoy your performance BMW for many years to come.
If you want to read more articles similar to M135i Oil & Filter Service: Costs & Insights, you can visit the Maintenance category.