ever use a PPG lacquer?

[GMC3]

I have only been painting a short time and have very little experience. I have used R-M lacquer and the underhood black from eastwood and both say to thin 1:1 to 1:1.25. I thinned both 1:1 and sprayed with no problems. The can of black PPG I just bought says to thin 1:1.5. I tried a small area and it just seems like too much thinner, the first coat is very transparent and it just seems too thin. Would it be okay to thin 1:1, or should I thin it 1:1.5 like it says on the can and not worry about it? The can also says to apply 4-6 coats, so maybe it's supposed to be that thin?

thank you