07vbluestang

i have been running royal purple in my whipple 07 mustang gt. this year i went to advance auto parts cause they have a special on royal purple 5 qts. and filter for $46. i bought the 5 + 1 but when i was checking out i noticed 2 out of the 6 were different labels but all were 5w-20. i ask the guy that works at advance and he said it's the exactly same oil just different label. well i went home and changed the oil and then started to read the labels more carefully. 4 bottles were the API service SN and 2 were API service SL with SYNERLEC. will this make any difference in protection? i do race at the track about 2X a month.

moosestang

I'm no oil specialist, but the one with synerlec is probably the HPS or hpx and won't hurt anything. It has more zinc/phosphorus and will protect better.

I wouldn't run a 5w20 when drag racing, but again, I'm no oil specialist. I'm using royal purple 5w30 HPS right now.

Art161

The guy at Advance Auto doesn't know his a** from a hole in the ground. SN is the latest API grade. When your 2007 was new, the latest grade was SM. SL is an older API grade. I don't know for sure whether it makes any difference or not in your vehicle.

Ditty

It won't make much of a difference and you will probably not notice anything different from the different oils. Like said before, SM was the 'series' (if you will) of the oil when your car was new. Using a 'series' newer will not hurt anything. You can go higher in series SN, SO, but it is suggested to not go lower. Really though, you are using a true synthetic oil so it is better than using some BS oil that is an SL series.

I wouldn't worry about it too much. Especially since only two quarts are going to be the older series of oil. They probably had some old oil that never sold and they are using the sale to off-load it. Take advantage and go get some more while they have it. Just try to get all of the SN series if you can.

moosestang

API ratings are really pointless. The oil I use has no API rating, because it has too much zddp to meet the latest standards. It's all EPA BS!