I know there have been a few posts' on this I just want to elaborate more on it.

After I changed to synthetic oil and reset my ECU I noticed a few differences....My car idles incredibly smoother, little better gas mileage. But when I use to hit 4000 rpm's befor the change, the needle would fly across the gauge and make a dif sound u know more high pitch. So I figure thats when myVTEC kicked in. Now it doesn't happen at all.

I read on the 'Lost VTEC???' post a reply from someone that said if you change to synthetic oil your VTEC wont kick in. Is this true?

I like the fact that it idles smoother and gets better mpg, but.... I need my VTEC! lol. Should I take it to a dealership? I would rather not.

 

My friend uses Royal Purple full synthetic in his B16 and Vtec kicks in hard.

 

Should I change to 10w 30 instead of 5w 30? Since it's warmer out and maybe it needs to be thicker?

Is it possible after reseting the ECU that VTEC would kick in sooner like 3000rpm's if you have a 4-2-1 header and other mods?

 

No just keep your 5w30.