A solid problem while driving!!!

I make it 16666 2/3Km apart and 83hrs 20 mins to drive it.

According to the calculator here it's 16697.5650 km. That's "as the crow flies". Assuming a car could take that direct route also it'd take 83.487825 hours to get there at 200 km/h.

I got 16672.5km. But the car would fall in the ocean and never make it.

Interestuing that we all three got such similar answers but no two exactly the same.

Reading the formula used on that calculator fishin post, it's certainly not accurate. They're assuming that the earth is a perfect sphere. It's really difficult to calculate because the longitudinal distances between the degrees vary from 110.6km at the equator to 111.7km at the poles. And I don't think they vary linearly. I just assumed they did for my calculation.

Not only the variation of 'length against degrees', there is always the question of how accurate a figure is being used for the putative circumference of the earth in the first place.

I took the circumference as 40 000 km and assumed that the earth is a perfect sphere; neither of these is likely to be perfectly accurate.

Bt what the heck? It's only a riddle. What intrigued me is that the three of us seem to be agreed on how it should be tackled; I would have expected that given that, we would all be working from the same 'near enough' figures.

what makes this thing a riddle and not a silly maths problem, of course, is the word 'distance'. Since it's not specified in what space you're measuring, everyone takes it as distance along the Earth surface, prompted by the second question. Unfortunately, the guy asking the riddle will then proceed to tell you that he meant normal 3D distance, which, AFAICR is around 12,000 km...
the time for the car is, indeed, correct

what is the really linear distance between those 2 points so ?

the answer should be full numbers, no decimal places.