Why is the 2016 Mini Countryman the only N18 engine that requires 0W-30 A5/B5 oil? All other years with the N12 N14 N16 and N18 require 5W-30 A3/B4 oil. My oil consumption is usually 1 liter for every 4,000 miles. I was being cheap and switch to 5w-30 A3/B4 Castrol euro oil and now it is being consumed at a rate of 1 liter per 1,500 miles. ( i know that is still acceptable by BMW standards) but why?

 

You can run 5w30 in place of 0w30 without issue. You could even switch to 5w40 Euro oil without drama.

 

Lower viscosity @tommydoo66 , that's why A5/B5 consumes more.
A5/B5 focuses on efficiency, being more fluid, whilst A3/B4 focuses on protection due to the high SAPS.

Probably for the intervals our engines need, all the below are nearly interchangeable.
I have done my last cycle with Mobil1 ESP 0w40 (C3), and I am about to drain/refill with Mannol Legend Esther 0w40 (A3/B4)


For reference:

https://bobistheoilguy.com/forums/th...-a5-b5.251011/

and

"ACEA A3/B4:

• Focus: High-performance and direct-injection diesel engines.
• Characteristics: Higher viscosity, potentially impacting fuel economy but offering better engine protection.
• Use: Suitable for extended drain intervals, but also for applications where A3/B3 oils are specified.

ACEA A5/B5:

• Focus: Fuel economy in high-performance gasoline and diesel engines, particularly those with low HTHS (high-temperature, high-shear) viscosity requirements.
• Characteristics: Lower viscosity, good fuel economy performance.
• Use: Designed for extended drain intervals, but not suitable for all engines, requiring consultation with the OEM.

ACEA C3:

• Focus:
  Compatibility with catalytic converters and diesel particulate filters (DPFs), often used in high-performance vehicles demanding enhanced durability.
• Characteristics:
  Mid-SAPS (sulfated ash, phosphorus, and sulfur) content, suitable for vehicles with advanced exhaust aftertreatment systems.
• Use:
  Ideal for high-performance vehicles with DPFs, often used in high-performance gasoline and light-duty diesel engines. "

 

No, the thicker oil is being consumed faster. I am switching back to Mini 0w-30 a5/B5 in my next oil change this month. We will see if there is a difference and if it will revert to a low oil consumption again.

 

I use in my Mini CMS 2015 n18 engine always

Liqui Moly Special Tec LL SAE 5W-30

Engine is healthy and doesn’t lose too much oil between changes. I highly recommend.