Viscosity

Viscosity is the first thing you will see when looking for oil. Viscosity is usually indicated by the numbers and letters at the end of the product name - eg. 5w30. As per the previous example, 5w30 is the original manufacturer oil provided and used in the majority of MQB cars. This is due to how 5w30 is made and its components. The first section ‘5w’ is the grade and thickness of the oil from cold and what temperature it can sit at from the external environment. Therefore the higher the number, the thicker the oil will be. The second section ‘30’ is also the grade and thickness of oil - but instead at engine operating temperature. Meaning that you then end up with a value between two temperature ranges for your region.

0W - Rated for -40C

5W - Rated for -35C

10W - Rated for -30C

15W - Rated for -25C

20W - Rated for -20C

10 - Rated upto 10C

20 - Rated upto 20C

30 - Rated upto 30C

40 - Rated upto 40C

50 - Rated upto 50C

UK and EU weather conditions generally do not exceed 30 degrees. During the winter months, it also generally doesn’t drop below -10. So why use 5w30 and not 20w30? The reason is simple. If you make the oil thicker then the car will struggle to lubricate the bearings and engine, causing damage. The oil should be ran within the temperature range recommended by the manufacturer and country. Why not run 0w30? You could. However you then have little to no thickness in the oil and you could still damage parts of the engine from the oil being so thin.

So why do people run 5w40 on track cars? This is mainly due to the higher abuse and heat generated in the engine, engine bay and from around the car. Meaning you want a higher ceiling for the oil to not degrade from it all. The more heat the oil can deal with, the less chance you have of it breaking down and causing further problems. Like any liquid, oil has a temperature ceiling. Once it reaches that ceiling it will start to breakdown and act more like water rather than a lubricating oil.

5W30 or 5W40?

As we described above, a lot of people are running 5w40 in their track cars for heat related reasons. This can be due to heat and abuse given to an engine during its time on track. We have seen more and more motorsport applications and vehicles using 5w30 due to Oil pumps suffering with flow problems due to the thicker oil. This is subjective to each car and its engine. Thicker oil on a higher mileage car may close up a piston gap and allow higher flow and heat properties within the oil to protect it. Using 5w30 is recommended by all VAG manufacturers however and seemingly is the way that motorsport teams are starting to revert back too. Please use your own judgement and your own testing as all vehicles and engines will be different. Using either oil will not cause drastic issues for you. If you see higher temps with 5w30, then run 5w40. If you have starting problems or oil consumption problems on 5w40, then use 5w30 and vice versa.

What Brand Of Oil Should I Use?

Most modern oils are semi synthetic or fully synthetic. Meaning that the oil is built up of various digestives and mixes for performance and longevity versus oil in the past which was only designed for long term use, but not performance. Speaking of performance, when looking for oil - make sure that the oil you are selecting for track use contains one of the following two things. Ester and PAO. Ester Synthetic oil is a new mix of chemical compounds which combats wear and friction at higher temperatures. PAO oil’s work hand in hand with an ester mix, due to how they are built up and able to also combat volatility. PAO oil’s generally circulate your engine and provide molecular coatings over the moving parts within your engine. Meaning that you get better protection, longevity and less wear from the abuse given to it whilst it is in high performance situations. Plenty of manufacturers have showcased this in testing versus oil without PAO’s, and it looks to be pretty impressive.

When should I change my oil?

Ideally oil changes should be followed by your manufacturers handbook. However if you are introducing your vehicle to higher loads and high performance situations more often, this interval should drop. Say your handbook says service every 10,000 miles. If you are not tracking your car but are modifying it and pushing more power through the vehicle - this creates more heat and stress overfull within the oil and engine. You should therefore lower you service intervals down to maybe 7,000 or less.

If you also then track your car and introduce it to further stress. Your intervals ideally should be below 5,000 miles. It doesn’t hurt to service your vehicle every 1000 miles if you can afford too. This just isn’t cost effective and is a little bit overkill. For those that can afford to, generally after every track day - the vehicle may get serviced. At MQB Trackcars however, understand this isn’t always an option due to various reasons. So try stick to a 5,000 mile limit.

What will happen if I go over the recommended limit? Not a lot really. The problem you run into is long term damage. Oil over term and over many heat cycles - loses its properties to lubricate and protect. Meaning that if you have 2 track days on one oil change and then drive the car over 20,000 miles, the oil may come out a completely different colour. This is due to the fact that its lost its ability to act like oil and has pretty much turned to water. The long term effects of this is increased damage and wear to all moving parts. This included pistons, bearings, valves and various other bits within your cars engine. Remember, servicing costs less than an engine rebuild!