Is there a way to calculate how diligent Kenyan motorists are about changing their engine oil, and how frequently they do so? — PL
Possibly several methods. But the quickest and cheapest way to get a broad impression could be to compare – by quantity – total national fuel sales with total national engine oil sales.
As a guesstimate, if we collectively consume six million litres of fuel per day and 60,000 litres of engine oil (through top-ups and complete oil changes) that would be a ratio of 100:1.
You can then apply that to the average car. Each time it changes its five litres of oil, at 100:1 it will have consumed 500 litres of fuel.
If its average fuel consumption is 13kph, on that much fuel it will have covered 6,500km. That would indicate reasonable diligence.
If the ratio is nearer 200:1, the interval indicator would be an oil change every 13,000 km, verging on serious neglect. If the ratio was 50:1, it would suggest an oil change every 3,250 km, ie verging on paranoia.
Given the wide variation in fuel consumption among cars, and that there is also a significant proportion of bigger commercial vehicles including heavy trucks, this is far from an exact science.
The point is that it is possible to get a general idea, in a matter of minutes and at no cost, by simply knowing something that is known (but not widely shared) – how much fuel is sold and how much engine oil is sold over a given period. By doing that on a regular basis, the results will at least reveal “trends” (are we getting more diligent or more negligent).
No doubt policy planners (and oil companies) are already doing that, and we can presume that the results aren’t startling.
Otherwise, there would be major public education campaigns, wouldn’t there? Pick your own emoji to go with that conclusion.
What might be done with 60,000 litres of old engine oil per day (about 22 million litres per year – enough to fill several thousand Olympic-sized swimming pools) is a separate question.
