[Shortie771]

I personally never engine brake. I accelerate downhill never more than 5mph over the speed limit (keeps me out of trouble since most people are still going even faster) and that allows me to coast​ up most hills (with engine off) or at least get me most of the way up, before having to apply light throttle to maintain speed. Doing it this way is more efficient than engine braking down hills and accelerating up them.

Also weight​ reduction won't really help much for hills. You can't just factor in the uphill, you have to also take the downhill into account. Being lighter helps you up a hill but, it hurts you going down hills because the heavier a car is the easier it will accelerate while going down hill.