My car tells me it needs a service in 220 days (May time). Can that be right? I will have only covered about 5k miles.
I contacted the dealership and they responded with the below:
All Seat cars now come with Intelligent Flexible Servicing which means that the on-board computer will work out when the car needs a service.
From my understanding it takes into account things like journey length, driving style ect.
Makes sense, my current car has inspections and service intervals. I could never work out which was which so i just book it in for a service every time. Didn't want to take the risk.
Besides that, if you are ragging your car around, or doing short trips. |You will either be burning your oil, or you will be building up water content in the oil. Neither is good and it will need changing.
Oil oxidation is the biggest cause of corrosion in the engine. The time it takes to oxidise the oil depends on your driving to some extent. The hotter the oil the faster it will oxidise. regualr long journeys will mean the oil will stay at higher temperatures for longer and therefore you are at risk of increased corrosion. For example, someone that does 1000 miles in a 10 day period, doing 100 miles in a single trip a day will oxidise their oil more than someone doing 1000 miles in a 10 day period that is doing 10-20 miles trips.
The oil itself contains bases and other additives designed to reduce corrosion, however, there is very little that prevents oxidation. The additives actually try to prevent corrosion as a result of oxidation.
When i was working at lubrizol, I was working on a research project that was looking at ways of reducing corrosion in ICE's. I found that whilst the industry thought that a high base number (amount of alkaline material in the oil) was considered good. The idea being it would guard against an increase in acidity due to oxidation and impurities produced through combustion. However, my counterparts in the chemical synthesis lab were desiging compounds with high base numbers, but the shape of the molecule itself would only allow for the alkaline material on the surface of said molecule to be effective. Meaning you have very large molecules doing very little, despite a high base number.
My research proved that the acidity in used oils, that had been exposed to the same running conditions, was infact increaseing regardless of how much base was added, the only difference being the time it took to reach an exponential increase in acidity.
Because of my research, by the time I left lubrixol they were starting to turn their attention to preventing oxidation, rather than trying to buffer the increase in acidity.
The effects of oxidation can only be slowed by topping up the oil between services. This increases the time it takes for the oil to reach its "failing point" at which time the acidity will begin to increase exponentially and you will start doing damage to your car.
The other issue that causes corrosion in the engine is water content. The products of combustion are water and carbon doixide. Plus anything else that is created as a result of burining the additives in the fuel. The water molecules will dissolve in the oil as it circulates round the engine. Now if your oil temperature is hot enough, this will evaporate over time and your engine will be fine. Thats why its important to make sure your engine gets a decent run every now and then.
If your engine doesnt get a good run to evaporate the water, it will condense on the inside of the engine. Acid is hydrophillic, menaing it likes to be in water rather than the oil. It is safe in the oil as it cant corrode there. However, in the water, the H+ ions dissociate and thats when the damage occurs. The hot spots in the engine are anywhere you would expect a drip of water to form. One of them i found to be on the crank shaft. where the water condeses and drips on to the crank shaft, if the engine is left in storage for two weeks or so, the oil coverage dissipates and there may be areas of metal exposed which allows for corrosion.
If you are not running your engine regularly, the only way to stop a build up of water in the oil is to change it. A telltale sign is cloudy oil that when left to settle will seperate. (this may take some time depending on the disspersant additive in the oil)
Lots of sciencey stuff, feel free to ask questions if you want to know anything specific. I used to work in Blend Testing at Lubrizol. I would test most oil additives that were due to be put in to mass production as well as near enoughe very field trial going on in Europe.