The short answer is they're all different. The long answer is they're all completely different! So many variations of engines, gearboxes, gear differentials and all that technical stuff, plus the way they may have been looked after (or not) in the last half century or so.

Many Routemasters have been re-engined with Scania, Iveco or Cummins engines. The Red Bus trio, as I tend to bang on about a lot, all have original AEC engines, though two have the 590 and one, RM875, has the more powerful 760.

But what are they like to drive? Another short answer is: they're great! It's a high driving position, which gives you a sense of confidence and helps with anticipation. The Routemaster was designed to be simple, which means they're semi-automatic, i.e no clutch but a manual gearstick. The late Colin Curtis, who worked on the design for London Transport back in the 1950s, told me about eight years ago: "We didn't want the cab to be like the cockpit of an aeroplance, with dials all over the place!". True to his word, the bus only has one dial, the speedometer, and doesn't even bother with a fuel gauge since refuelling was done daily at the garage.

Gear change

Only one of our buses, RM1353, was wired for fully automatic transmission, so that you could drive between second and fourth gears without lifting a finger to the gear stick. That bus was also converted to manual gear changes last year but it's still so easy. How to start the engine has to stay a secret but there's no ignition key.

People are often surprised to learn Routemasters came with power steering from the start. It's not as light as on modern vehicles of course but it's pretty good. Quality also varies from bus to bus markedly. It's the same with the engine noise on RM1353 and RM737 - both AEC 590s but a different sound and feel.

Someone said Routemasters don't accelerate, they slowly gather momentum and that's about right. I remember as a passenger what a thrill it was to hit top gear and fly down somewhere like Holland Park Avenue at night at 35mph, if the driver dared. When RM875 hits 50mph on the A1 near Edinburgh you certainly know about it as well. But the point of these buses was never speed – it's slow, stately progress around a city.