Manufacturer engine oil changes... MYTH BUSTED? Shauno answers the age-old question of whether changing your oil more often REALLY makes a difference!
Factory service manuals often recommend oil change intervals around 10,000kms, but Shauno explains why that might be WAY too long for your 4WD!
PUT TO THE TEST
Is changing your engine oil more regularly really making a difference? We test 5 000km, 10 000km and 20 000km old oil and we are going to show you the real effect of leaving your oil in your engine for too long.
You may be shocked that the service manual in your 4WD recommends that you change your oil every 10,000km. Now you think just as Shauno does, and believe that 10,000km is way too long between oil changes, especially if you use your four-wheel drive hard!
COMPARING DIFFERENT KM AGED OILS
We sampled brand new Castrol 15W 40 oil, 5 000km old oil, 10 000km oil and 20 000km oil. We poured a little bit of each sample on a sheet of paper to take note of two things:
How the oil runs down the paper, showing the viscosity and how freely it moves. The slower the oil the worse it can move around in your engine.
The colour of the oil. The darker the oil means the more contaminates in the oil.
Brand new Castrol Oil
The oil is nice and clear and runs down the page smoothly.
This oil runs freely down the page nicely too, but the oil has some darkness from contaminates picked up from mixing in the components of your engine. These contaminants are things like exhaust gas, soot as well as others. The top section of this test oil stream is still actually quite clear.
Shauno changes his oil on all his 4x4s at this point, regardless of the recommended factory service manual.
It moves slowly down the paper and is noticeably darker in colour to the previous tested oils.
Now this is the recommended oil change time from most factory service recommendations in common rail diesels and even big V8 engines like the 200 Series Landcruiser.
The colour, texture and viscosity of this oil is like tar. It moves down the page as if it was glue. There is no part of this tested oil that is clear, and oil that is this contaminated could not be doing its job properly.
Hopefully this is not how long you wait to change your 4WDs oil, because this is definitely not doing your engine any favours.
Why Engine Oil Needs Replacing?
Engine oil has two main jobs: Lubricate so there is no metal-on-metal wear, and control contamination by catching the soot created by the engine without leaving deposits that may wear down components of the engine – therefore engine oil turns dark over time.
Imagine engine oil as water, and mud as soot. If a little bit of mud makes its way into the water, it will get discoloured and dirty, but the viscosity is still pretty good. The more mud introduced (the older the oil of your engine) the thicker and darker the water will be and there are more contaminants.
The longer you leave the oil in your 4WD, the harder you work your engine by going off road, towing or in constant traffic, the more your oil will thicken and become less effective at controlling contaminations. This leaves a chance for these contaminants on components that begin to wear and rust your 4WD.
Leaving your oil in a petrol engine causes a different issue. Petrol engines don’t generate soot particles in large quantities like diesels, but the oil does get contaminated by fuel and water vapour when a petrol engine doesn’t reach optimal operating temperatures.
If a petrol engine is repeatedly driven in conditions where the oil doesn’t reach the right temperatures, nitration can occur which turns the oil brown and sludgy. This thick sludgy viscosity prevents enough oil reaching metal surfaces which can lead to premature wear.
Another reason you should change your oil before it gets too contaminated is the deposits the oil leaves in the engine are picked up by the fresh oil you put in, immediately degrading that oil.
What causes fast oil contamination?
Towing heavy loads, going four-wheel driving or any other high-stress engine work that produce more soot will lead to faster oil contamination.
Engine Operating Temperature
Short trips in your 4WD put your engine through more stress that almost all types of driving, especially in winter.
Modern diesels take more time to get to perfect operating temperatures of around 90 degrees Celsius, this takes longer to reach in slow congested traffic.
When your diesels cold the combustion process isn’t as efficient as you are going to get a lot more soot and contaminants inside your oil, in comparison to when your vehicle has had a chance to warm up on a big drive or highway kilometres.
Exhaust Gas Recirculation
Your Exhaust Gas Recirculation (EGR) will be amplified when your 4WD is cold or in traffic driving and that is not great for your oil as it is going to contaminate furthermore.
Some cases you will find that if you do a lot of stop-start driving, no large kilometres and turning off your 4WD before it reaches ideal running temperatures, your 5 000km oil will be contaminated more like 10 000km oil or worse.
Oil Comparison 2: Regular Driving vs In-Town Short Trips
We compared two test oils of 10 000km use. One was from a 4WD diesel with regular use and the other was taken from a common rail diesel strictly used in short trips to and from work in traffic.
The regular 10 000km oil acted same to the previous test – dark and slightly viscose compared to new – and the high traffic slow driven oil related more to the 20 000km old oil. This oil was very thick and very dark clearly showed this driving style contaminates your engine oil far worse.
Quality of your oil
Your driving style and the intervals in which you service your engine oil makes a huge difference in the quality and service intervals of your oil for your 4WD.
Shaun recommends choosing high quality oil like Castrol Magnatec because the better-quality oil, the better it is going to protect your engine for longer.
Most engine oils do not work their best until the engine reaches operating temperatures because the additives need heat to activate. However, Castrol Magnatec contains a unique additive found only in Castrol products that cling to metal surfaces even under cold starts. This will protect your engine while it is warming up and significantly reduce engine wear.
Our recommended oil service intervals
Unless your 4WD is only ever used for long highway drives and is rarely driving in traffic, we recommend shortening your oil service intervals to get the best out of your diesel motor.
Shauno recommends cutting your service intervals in half to around every 5 000kms, but newer vehicles like his 200 Series should be serviced around every 7 000kms.
The better-quality the oil, the more you can trust that the vitals of your 4WDs engine will be protected. It really is just cheap insurance for your pride and joy.
Castrol Magnatec Diesel 15W40 5L - 3383364
Castrol Magnatec Diesel 15W-40 Engine Oil combines dedicated diesel technology with intelligent molecules for a stronger layer of protection, reducing wear during the critical warm-up period. Metal on metal contact is the enemy of any engine and lubrication and oil coverage of internal moving parts is critical. Castrol have developed their range of Magnatec engine oil to cling tenaciously to your engine components even when the engine is off to provide that level of protection that other oils don't. Offering instant lubrication as soon as you turn the key, Castrol Magnatec intelligent molecules are present throughout all driving conditions to dramatically reduce engine wear and provide vital protection.
Castrol’s high-performing oils and fluids are specially designed to keep your engine and drivetrain lubricated and running smoothly and staying well protected, Castrol call it liquid engineering. Castrol have a solution to suit your engine oil needs, whether it be a 4WD like big Sooty, Jocko’s Pony Lux or your daily driver, Castrol have the right oils and fluids to get the best performance out of your vehicles engine while maintaining temperature and protecting the internals.
- Dedicated diesel technology
- This oil provides excellent soot handling performance thus minimising oil thickening
- Maintains engine efficiency and responsiveness in common rail diesel engines.
- Cling to your engine forming an extra layer that protects during start up and beyond
- API SN/CF
- ACEA A3/B3, A3/B
- Part Synthetic
Castrol Magnatec Diesel 15W-40 is suitable for naturally aspirated, turbocharged and inter-cooled turbocharged engines. Also suitable for direct and indirect injection diesel engines. Not recommended for heavy commercial vehicle application or vehicles fitted with diesel particulate filters.
Castrol Magnatec Diesel DX 5W40 5L - 3383629
Castrol Magnatec Diesel DX 5W-40 Engine Oil combining DPF compatible technology with intelligent molecules for an extra layer of protection, reducing wear during the critical warm-up period. Its unique formulation protects from the moment you start, dramatically reducing engine wear. Now with ultra-refined molecules, for protection you can see, hear and feel.
Metal on metal contact is the enemy of any engine and lubrication and oil coverage of internal moving parts is critical. Castrol have developed their range of Magnatec engine oil to cling tenaciously to your engine components even when the engine is off to provide that level of protection that other oils don't. Offering instant lubrication as soon as you turn the key, Castrol Magnatec's intelligent molecules are present throughout all driving conditions to dramatically reduce engine wear and provide vital protection.
- Maintains engine efficiency and responsiveness through dedicated DPF compatible technology
- Provide excellent soot handling performance thus minimising oil thickening
- Provide superior performance under extreme cold start-up conditions compared to thicker grades
- Castrol MAGNATEC DIESEL DX 5W-40 has been specially formulated to deliver outstanding protection for the latest engines fitted with after treatment devices such as Diesel Particulate Filters and 3-way catalysts.
Castrol Magnatec Diesel DX 5W-40 is a synthetic engine oil suitable for use in automotive gasoline and diesel engines where the manufacturer recommends an ACEA C3, API SN/CF or earlier specification 5W-40 lubricant.
Castrol Magnatec 10W-40 Engine Oil 6L - 3414526
Castrol Magnatec 10W-40 engine oils a part synthetic engine oil formulated to suit a wide range of petrol engines, direct and indirect injection diesel engines, LPG and CNG cars, light commercial vehicles and most of all, 4WD's.
Metal on metal contact is the enemy of any engine and lubrication and oil coverage of internal moving parts is critical. Castrol have developed their range of Magnatec engine oil to cling tenaciously to your engine components even when the engine is off to provide that level of protection that other oils don't. Offering instant lubrication as soon as you turn the key, Castrol Magnatec intelligent molecules are present throughout all driving conditions to dramatically reduce engine wear and provide vital protection on and off the road.
- Intelligent molecules cling to critical engine parts, forming an extra layer that protects during start-up and beyond
- Bonded oil coverage makes engine parts more resistant to wear
- Semi synthetic oil technology to provide increased protection in high and low temperatures
- Provides continuous protection for all driving condition
- API SN/CF
- ACEA A3/B4