BY: Simon Michell, Business Development Manager, Certas Energy Lubricants
Things are happening at a pace in the world of Hybrid cars. Currently there are over 200 different models of Hybrid cars in the UK and now there is a range of dedicated Hybrid engine oils are on the scene.
The good news is there are currently only three Hybrid oils 0W-20 C5, and 5W-30 in C2 and C3 – which is a relief!
I met up with Nadia Nieuwland one of the technical experts at the Valvoline laboratory in the Netherlands, to get some answers about these new Hybrid engine oils.
The Hybrid market is the fastest growing car segment in Europe: +21% each year and is forecasted to peak in 2028.
The big influence is the Zero- and Low-Emission (ZLEV) zones that are springing up in several UK cities.
Cars are responsible for 15% of total EU emissions of CO2 and the EU has set OEM fleet-wide CO2 emission targets for 2024. To keep within the emissions regulations, Hybrid vehicles are seen by the car manufacturers as one of the solutions.
Some of us can remember when ICE meant In Car Entertainment for cars – Not anymore, welcome to 2022!
ICE is a term used by the new breed of Hybrids, when referring to conventional petrol or diesel, Internal Combustion Engine
The conversation with Nadia started by them explaining to me that there were three distinct types of hybrid powertrains.
- MHEV (Mild Hybrid Electric Vehicle)
The mild hybrid is the entry level into the world of Hybrid cars. It’s uses a conventional petrol or diesel engine with a very small generator, which is typically 48V.
The range is limited to around the block, but it does help with efficiency and fuel consumption for short trips. The Jaguar F Pace MHEV is a good example of a mild hybrid.
- FULL HEV (Self Charging Hybrid Electric Vehicle)
A popular option is the Hybrid Electric (HEV). This also uses a conventional internal combustion engine. However, the electric motor charges a small battery as you drive. Usually with the added advantage of brake regeneration. On a good day, 20 to 30 miles are feasible when running on purely electric.
- PHEV (Plug In Hybrid Electric Vehicle)
If you drive through the suburbs the Plug In Hybrids are easily recognised in the driveway’s by the umbilical cord, linking the car with the house and the national grid.
These hybrids have a petrol or diesel engine and a beefy internal electric motor, often found inside the gearbox.
The battery pack can be plugged in and charged overnight. 40 to 50 miles are often achievable in a PHEV.
An example would be the Jaguar F Pace PHEV P400e. It packs 33 miles range on pure electric. It charges from the wall to 80% capacity in 100 minutes and it has a fast charge to nearly full in 30 minutes.
Zero to 60 mph in 5 seconds! That’s entering supercar performance figures!
This bring us neatly onto the new range of Hybrid oils. The burning question I needed answering from the Valvoline chemists was – is it just another smoke and mirrors way of complicating things or do these 0W-20 and 5W-30 Hybrid oils offer a real and distinct benefit?
Hybrid engines have a completely different duty cycle to conventional engines.
The duty cycle can be thought of as what happens to the engine on a journey. An example would be, a slow initial speed followed by rapid acceleration and maybe idling in-between.
Take for example joining a motorway You give it the beans and in a conventional engine, it just delivers the power.
With a hybrid, clever electronics figure out if the engine or the battery or even both power sources are going to get you briskly from slow to 70 mph.
Now he is the rub. The engine is possibly cold or at least cooler than it should be. Why? Because since leaving the house the car has been running on electric.
Engine oil is designed to work best at optimum temperature, typically in a non Hybrid application 90-100 degrees Celsius.
Because the engine in a Hybrid is switching on and off and therefore running hot and cold, condensation in the oil becomes an issue.
Engine restarts are in the order of 500,000 compared to 50,000 on a conventional engine over 100,000 miles. There are also harsh power demands that are tough on the engine and oil.
Welcome to world of Hybrid oil. Engine oil that is specifically designed to handle these changes in temperature and sudden demands for critical engine protection and instant power.
The first issue with hybrid engines is condensation on the cylinder bores. This condensation gets into the oil and is then pumped around the engine. Like the condensation on a window, creating a puddle of water on the window ledge.
Valvoline tests in Hybrid application in Norway demonstrate that there can be up to 15% water in the oil. This is because the oil has not had a chance to get hot enough to evaporate off the water. You can imagine the inevitable consequence of potential corrosion issues in the engine.
Another challenge is an increasing amount of copper is used in Hybrid powertrains. The high proliferation of electrical components inevitably leads to more copper usage. Copper has excellent electrical conductivity but corrodes easily. Hybrid oils have special additives to protect and keep this corrosion under control.
The third challenge is that at normal operating temperatures, typically, a conventional engine runs at its most efficient at around 90-100 degrees Celsius.
Hybrid engines operate at different cycles and therefore create more challenges with the variation of temperatures.
The combination of variable engine temperatures and condensation can lead to early oil oxidation, which in extreme circumstances creates that horrible acidic slimy, sludge in the engine, which exacerbates the copper corrosion
Put simply the conventional oil cannot handle these wild variations in engine temperatures.
The Valvoline chemists work hard on the Hybrid oils to ensure improved oxidation control and engine protection and water tolerance
All in all, I think it is fair to say that Hybrid oils do offer significant advantages over conventional fully synthetic engine oils in terms of
– Water tolerance, reduces oxidation, and corrosion protection.
To link in with this impressive performance, the Valvoline Hybrid 0W-20 C5 oil has just been upgraded to Mercedes Benz 229.71 and the Hybrid 5W-30 C3 to Mercedes Benz 229.51.
There is also a range of specifically formulated Hybrid transmission oils, for Hybrid ATF and DCT applications.