I lived on a tropical island for a while where the roads were so bad, narrow and busy that speeds above 40 km/h almost never happened (there was a one km stretc

I lived on a tropical island for a while where the roads were so bad, narrow and busy that speeds above 40 km/h almost never happened (there was a one km stretch on the opposite side where I could reach 50-60 if lucky). Turned out that the low speed combined with short drives (it was a smallish island) was bad for the engine: the oil never really mixed well and had to be replaced much more often than expected for such low milage.