the old owner has put synthetic oil in the s2k. my question is, can i revert back to using original oil. is it damaging to the engine in any way to revert back?

 

No damage - I'd just do it at an oil change and change the filter too - don't mix them by ading a quart at a time, so to speak.

 

But why?

 

Mixing won't hurt.

 

 

My understanding is it's probably not best to mix oil and oil brands because of the precise amount of additives that each oil company designates for it's own oil. Adding a different brand of oil to your current oil can upset this additive balance.
You can change brands of oil as often as you like but its always best to do this during an oil change.

 

is synthetic realy that much better for the car? why do most ppl run synthetic? i just got an oil change for my car and mobile 1 synthetic and filter already cost me $50. is it really worth it?

 

I use synthetic oil and consider it an insurance policy. I had to use synthetic in my race cars due to the high temps experienced in racing. While I do not race my S2K, I know that this little motor is working just as hard or harder as my race car which redlined at 7,000 rpm. A few bucks more, but nothing but the best for my S2K, besides I do all the work myself to save money.

 

From everything I've read, synthetic is realistically no better nor worse than dino oil. Supposedly you can go longer between oil changes with synthetic, but I rarely see people do this, so they're not really getting a benefit imo. I use dino oil, save money on fluids, and change it every 5k or 6 months. I doubt I'd do it differently with synthetic, so I figure I'm saving $40/yr or so.

 

If you're going to keep the car a long time. It probably pays to use synthetic. If it's a 2-3 year lease, put the cheapest stuff in it you can.