That's hard to say..
Personally I use SF in my daily driver once in awhile & its a noticeable difference.. but then again, I'm using it "as directed".
For future reff.. LOOK UP/FIND the starting procedure using glow plugs specifically for your machine.. & follow the instructions..
Write down the date u bought the GP's.. & compare it to the "next time" u have to buy some..
Don't forget/Keep In Mind, Glow Plugs are a WEAR ITEM.. they are designed to be replaced.. Just like a fan belt or a battery..
AND there ARE differences in manufacturers.. so if it becomes a REAL problem.. switch manuf.. Bosch, Denso, NGK.. to name a few..
Happy that u got it up & running w/o anything major happening..