Current record holder? Sauber, C9 = 340.4 km/h.
This year’s best? Toyota, TS 030 Hybrid = 331.1 km/h.
Given the way rules work now versus then that’s pretty damn impressive. That’s only about 9 km/h (or about 5.5 m/h) difference. Also remember when the C9 set the record the back straight was one continuous straight over a mile long. There are now two chicanes there.