So if I put castrol syntec in my 87 n/t..only once... would it be bad if I switched back to non syn. since castrol isnt all that great of a synthetic oil anyway? pros and cons please.

 

castrol isnt a good synthetic huh.... well thats the first time i have ever heard that.. might try penziol than

 

well...its not good for rx7 because it has a lot of ash in the oil. I was just wondering since I just used it once, if it would be really bad if I switched to a non synt. like penzoil.

 

i was being sarcastic about penziol... i would never run that stuff. i only run castrol gtx in my mazda, and mobil 1 synth in my honda

 

yea castrol gtx is the bomb, but castrol syntec isnt, and thats besides the point. Does anyone have any input on switching from castrol syn. to regular non syn.

 

use ELF synthetic oil.. thats the top line!

 

Id rather use mobile 1 or royal purple....but thats besides the point to.

 

Ash is not in the oil.. ash is what is left after the oil has been burned. Oils that have high ash, leave lots of deposits after they are burned.

And just for some numbers, Castrol 20W50 GTX has a ash % typically of .85. So less than 1% left after burning. While Castrol Syntec 5W50 typically has a % around 1.2 to 1.5 so more than half again up to nearing double the left over material after burning than its cousin 20W50 has. Both Redline and Royal Purple have less than .5% left after burning.

and one oil change worth (3000-5000 miles) of running any oil, synthetic or conventional (as long as it is the correct weight for your starting and driving temps) is not going to hurt anything.

 

ELF is better then RP or Mobil 1 mobil 1 is not a TRUE FULL synthetic elf is!

 

^well if that was the case, and mobil 1 is not a full synthetic, they can get sued for false advertisment. casue i am looking at the bottle of mobil1 and on the front is says FULLY SYNTHETIC. last time i checked that meant it was full synthetic.....

 

time to read your facts

Most mobil 1s (some arent) are Group III basestocks which are not true synthetics. All of Castrol syntec (with the exception of the 0w30 GC) is a group III. GROUP IV and Vs are pure synthetics i.e. ELF

 

actually there were several suits a few years back between Castrol and Mobil and a the industry in general, about what was determined to be synthetic oils.

The results of the suits, came out to be that a Group III basestock oil can be sufficently refined and changed enough from it's initial formulation to be considered a synthetic oil and sold as such.

However I personally do consider that cheating, but to the letter of the law they can call themselves a "Synthetic Oil".