The main issue is the intensity of incandescent light bulbs are measured in Candlepower, while LEDs are measured in Lumens.
As well, incandescent bulbs are more or less omnidirectional while LEDs are highly directional. That can cause an increase of shadows when using LEDs in certain situations.
Finally, incandescent bulbs are typically around 3000degK, which casts a yellow/orange color, whereas LEDs are typically available from 5000degK up to 7000degK, which are daylight to blue color respectively.
All this means there is no direct comparison between a LED and incandescent bulb.
What I did is to buy a couple of LEDs that were not expensive; $5~$8, from eBay, Amazon, etc. and tested them as compared to the incandescent bulbs. That way, I had a minimal investment in the LEDs if I decided they were not the right ones.
I probably went overboard in testing but I tested for color, intensity, temperature (using a Fluke 62 IR temperature meter) and current requirement (using a B&K 316 mini-clamp meter).
I ended up liking the 5000degK LEDs the best as they approximate the color of the noon-day sun (the 7000degK LEDs were too blue for my liking). And I found that the LEDs I picked only required 10% of the energy the others required.
The bulbs in my coach were #1141, so I bought LED replacements having the same base so that they were a simple swap out.
After I found the LEDs I liked the best, then I bought them in quantity. The couple of LEDs I tested with that were not picked were still used for the storage lockers - at least the ones that had lights in them.
I feel safer if I inadvertantly leave a LED light on in the storage locker rather than incandescent bulbs.
If you want to replace the LEDs in your tail lights, make sure to buy DOT approved ones for that purpose.
It was under $100 for replacing all of the lights on my coach - around 22 of them, and I mistakenly left on the lights in the bathroom, and they stayed on for about 2 weeks without draining the batteries.
This is what I ended up buying:
You can buy a different version having 5 more LEDs that is a bit brigher, but the brightness of the ones I bought pretty much matched the brightness of the incandescent bulbs I replaced.
For the porch light, I bought a different version of LED. It was only $10 at Amazon and has 66 LEDs, and is claimed to be the brightest LED in that kind of base. I have not confirmed that, but I can tell you it is very bright and lights up the entire underside of the awning at night.
Amazon.com: The Brightest Ba15s LED Light Bulb Replacement - Warm White Color - 2nd Generation with 66 LED's - Single Contact Base - 10-30V DC: Automotive
That big, fat LED will fit into this kind of enclosure: