Block heaters: which one.

I think you're worrying too much also. But since you asked about detrimental effects.

The inline tank heater involves cutting in to your heater hose so there's extra potential for coolant leaks. I've had it happen more than once. Plus it clutters up the engine compartment but that's just a personal preference thing.

The silicone oil pan heater acts as an insulator keeping more heat inside your oil pan (and oil) - not what you want on a hot day.

Battery warmer - these can boil the water out of your battery if over used. Don't leave it plugged in all night - use a timer.

If you're paying for the electric power that could be detrimental to your wallet!

 

I agree, I've never had a block heater of any kind, except on a diesel Ford Dexta I had. Heck you're gonna be in tropics compared to me.

 

Thanks for all the info. I'll take some pics of the Mojave heater install when I get it.
Thanks again, Marc