i just did this both the same day on tuesday and its kinda cool, ive noticed a different sound to my car as well as a slight increase in performance. im not sure if its the synthetic oil doing this or just the 94 octane doing it or the mixture of both but its cool

 

If you haven't been running 94 the whole time then I can see where your increase is comming from. 2.4L are meant to run high octane normally.

Just synth oil though? I don't think that makes a real knowticable difference.

It might just be in your mind that the combo is increasing performance. I could really tell you though. Just a thought.

I've been running regular oil in my car and when I switched to synth I didn't make any note of a performance increase personally.

 

Its Probably The Gas, I Had Been Running 91-93 This Whole Time And This Was My 1st Oil Change And I Switched To Synthetic, I Thought It Might Be In My Head At First Till My Frined Asked Why My Car Sounded Different So I Dont Know, Sorry About The Caps I Didnt Know They Were On And I Dont Fee Like Retyping This Lol

 

I'll back you up on that. At least the oil. I run 91, 92 or 94. I haven't noticed any difference.

After my Amsoil switch over the engine sounds a little different. Better. Along with my Mobil 1 trans fluid I would suspect it might free up 2 hp. My mileage seems to have gotten a tiny boost.