Trying to figure out engine runtime since out of the manufacture

Just for curiousity, I'm trying to figure out the engine runtime since the car was out of the manufacture. Tell me if my logic is sound.

Using a previous trip data of 297.62 km (longest non stop with Hybrid Assistant running), where 38.24 km were done in EV, 47.18 were done without any fuel and 14.082 L of gas were used (according to Hybrid Assistant), I'll use the formula 14.082 / (297.62 - 47.18) * 100 and get the answer of 5.62 L/100 km for fuel consumption when the engine is running at highway speed (avg was 97 km/h for that trip).

According to the odometer, for a distance of 142,944 km, the car obtained a consumption of 0.8 L/100 km. Using the formula 0.8/5.6 * 142,944, I get an engine run time of 20,240 km. Being a 2017 model, that turns out to roughly 3,500 km of engine runtime per year.

Does my logic seems right or am I in the left field?

Thanks.

 

So, I'm the only one that's curious about how to approximate/find the engine runtime? That can't be...