And to be specific, it was a knocking sound coming from the left side of the engine, it sounded like it was only coming from one piston.

 

i have this knock too

 

I would recommend having AAA as my M45 made the same noise for a little while before it before the conrod broke, punching a hole thru the block and seizing up.

 

High compression engines need super.

 

You'll be fine without premium unless you were tuned for premium. even then, its not your problem. If you tune your car you should keep using premium only though.

 

^ using regular with our cars is not good, the engine will start to knock i have tried this already it drives like crap with regular.

 

I bought a G35 with 65K miles on it and was notice that the car consume a quart of oil at the first 1000 mile after oil change and the engine make knocking sound when it first start up or long drive!

My own experiment and it work.

1. I replaces oil at 1000 miles 3-4times ( possible dirty oil ring)
2. I replaces oil at 3500 miles not at 5000 as factory recommended.( dirty engine)
3. I used Redline valve cleaner 4 times with 92 octane (carbon build up) and do 3500rpm to 4000rpm for 2-3 minutes each full tank. This may take couple months to complete 4 bottles of Redline depend how much you drive.

Now, my G35 don't make any noices and does not consume a extra quart of oil anymore.

Good luck!

 

were u able to fix the problem? mine is sounding the same