We see that, except for the AMX Leclerc, tank tonnage is in the lower 60s.
The power to weight ratio of the Leopard 2 and M1 Abrams are both about 24HP/ton. The Challenger 2, however, is at 19hp/ton.
This has been a trend in British tank design.
Also, we can see that all but the British tank use a smoothbore cannon. This is because the British like to use HESH rounds which work better in rifled cannons. From what I’ve read, HESH rounds have rather easy counters in tank armor in the form of spall liners but they do quite well against fortifications. Yet, the priorities of a main battle tank are usually 1) take out other MBTs 2) Take out other armor 3) take out everything else.
So, my questions are:
How come the British have historically preferred slower tanks? Do they have more armor than American and German tanks even if they weights are roughly the same?
How come the British prefer to use HESH rounds?
How come the Leopard 2, which uses a traditional diesel engine, is as powerful as the M1 Abrams turbine while both tanks weigh the same? What was the point of using a turbine engine in the US tank if the Leopard 2 gets the same power/weight ratio and goes a bit faster than the M1 Abrams?
A preference for slower tanks could be based in differences in tank doctrine, though I don’t know what those differences might be.
Regarding the turbine on the Abrams, one of the advantages of it is that it could burn pretty much any sort of liquid fuel, from diesel to jet fuel to gasoline. A handy way of making logistics a bit easier, given that the Abrams has terrible gas mileage.
While the accuracy over long distance of modern smoothbores isn’t that much different from rifles, the Challenger 1 had the longest distance tank-on-tank kill in Desert Storm at 5,100 meters which seems to still be the record.
The priorities of main battle tanks can be taken too far in the direction of 1) other MBTs to the point of ignoring 3) everything else. This was a serious criticism of the M1A1 over the M1; the larger gun reduced the ammunition stowage from 65 to 42 rounds and the standard load out was almost all DS rounds, there was no dedicated HE round, just HEAT, and unlike the 105mm gun there was no canister round and no WP round. Even though it had been pointed out as a weakness since the M1A1 entered service, the M1028 120mm canister round had to be rushed into service in 2003 in postwar Iraq where there were no tanks for the Abrams to shoot at, but plenty of call for a dedicated anti-personnel round.
British tank design has traditionally favored protection over speed, and this still shows through somewhat in the modern tanks. (as a point of comparison, German tanks had the opposite philosophy- mobility was the primary consideration.)
They don’t necessarily use HESH rounds exclusively. They use APFSDS rounds a lot, but HESH rounds are very versatile- more so than HEAT, and since they’re not a KE round, they potentially can be longer ranged, especially out of a rifled gun.
Easy… even though the power to weight ratio is the same on the Leopard 2 and the M1 Abrams, the performance characteristics aren’t the same. The M1’s turbine flat out out accelerates the diesels on the Leopard 2. So while on flat ground, the M1 and Leopard have similar top speeds, the M1 accelerates a lot faster, which is a lifesaving and battle winning ability. Beyond that, the turbine is a multi-fuel device -it can run on diesel, gasoline, JP-8, kerosene, and probably bunker fuel, paint thinner or acetone if you could get enough of it. They’re also very reliable in practice and easily swapped for depot level repairs.
The only big drawbacks are very high fuel consumption and really hot exhaust.