[zabzonk]

Don't know about the Germans, but the British used modified aero engines quite extensively in tanks - https://www.wikiwand.com/en/Rolls-Royce_Meteor

[snovv_crash]

Indeed, my grandfather was in one in Italy late in the war. From the stories he told, the crew one time got it up to 40MPH, then the crankshaft snapped.

[newnewpdro]

That's pretty smart, using de-tuned aviation engines.

But unlike what WalterBright is describing, these were appropriately reconfigured to not require high-octane fuel.