Nothing to do with the size of the engine but the design of the heating system fitted, with my discos heater blower on full to the screen frost is cleared in the time it takes me to flat the side windows so no time at all.
I could also switch on my heated screen which is great when there's snow about, and all much the same as another more modern car with a V8 I own.
But in my RRc days it took ages as the 3.5 had a perthetic heater system full stop, not the worse heating I've ever known but still pretty poor.
My defender has it as standard. I think they are fantastic. It clears mist and ice far quicker than any heater ever will. Had one on an old ford too. Would always have one given the option
i push this handy little prog button on my hevac it turns on the heated front n rear screens when it decides the engine warm enough it blows warm air onto the screen as well. oh and after 10mins my uprated heated seats are well toasty. didnt need to upgrade a thing in my vogue lol all standard
my local National Windscreens depot supplied and fitted a heated screen to my 110 rebuild for something silly like <£150 after I broke the original screen refitting it (TBF to me, it did have a huge chip in it so was quite likely to break, even without my hamfistedness). I added a 10min timer relay driving two power relays (one for each side of the screen - 3x contacts) and it works a treat.
BTW, they actually prefer to fit it with the frame in the vehicle
controller and relay (together with headlight relays). Timer energised with a momentary pushbutton switch in the dash.
There is an oem style kit on eBay for £100 and Pilks screen is £150 plus vat so looking like a £300 mod, can it get heated door seals and locks, otherwise I won't be able to get in to push the button, lol