They’ve done studies and the two types offer pretty much the same protection up to like 5-6k miles. After that the synthetic holds up better. So if you change your oil regulary you dont have to worry.
Well, on the advice of some fellow Miata people, I decided to try something completely different for oil: Shell Rotella T, 15W-40. It is designed for diesels, but that doesn’t mean that it is not also good for gasoline engines. I guess the additives that they use are pretty robust, and another guy who had the exact same problem as me said he got to his 3000 mile point without any lifter tick at all using this oil. The best part about it is that is is only a little over $7/gal for dino, and the synthetic version is just over $13/gallon. Sure beats the $20+ for Mobil 1 if it holds up. I’ll report back in about 2800 more miles. So far it held up to the two-driver auto-x test pretty well. No tick at all during startup or after two consecutive hard runs.
Oh and if you have a diesel (Tom), this oil is probably a great choice, as it supposedly has some good anti-soot properties.
Synthetic I read also has smaller molecules or some shit like that… allowing it to get into smaller places and crevices in your engine.
I forget the name of that awesome oil site… with forums and everything dedicated to oil… it was like… Bobtheoilguy.com … or something. Anyone else remember that?
EDIT: found it http://www.bobistheoilguy.com/
and I just relized someone already mentioned it above… BITOG
They sell that oil additive… it has the small molecules or whatever, which they claim seal scratches and shit in your pistons, reducing blowby etc… and increasing power.
I forgot what the hell it’s called… I never trust those car product infomercials… but the little animated diagrams were cool.
EDIT: this is it: http://www.duralube.com/index.cfm/&adv=googleads&tar=oilgroup
Check out http://themotoroilsite.com/forums/ for some good reading on oil. The Motor Oil Bible has some pretty in-depth quantitative evaluation of oil brands. Amsoil seems to finish in the top 5, if not first, in every weight. Redline and Mobil 1 are usually all right up there too.
I’ve heard that if you switch from petroleum to synthetic on a high mileage motor you might start finding oil leaks in new places. Synthetics have smaller molecules or something, so that they can slip through where thicker petroleum cannot.
Synthetic oil molecules are all the same size and shape, while petroleum oils are not uniform and can fill in spots that synthetic will not.its like filling a garbage can with golf balls, there are going to be spots that wont get filled because the balls do not fit together. Now fill the same garbage can with pieces of broken glass the odd shapes will find there way into places kinda like a puzzle.
i use a semi synthetic 20w50 deisel oil in the summer on my 1988 1.8L turbo engine. and i also used it on my ka24de engine in summer only.
now i beat the living shit out of my engine on a daily basis. I bring it up to redline atleast 4 times every time i drive my car. Its daily driven and i used it on both engines. it is a no-name oil i bought from wallmart.
majority of deisel engines are turbocharged +1
in canada our gas has high sulphur (sp i cant spell for shits), deisel is high in sulphur. +1
not a full synthetic so the oil isnt gona seep out of my main seal +1
none of my engines have ever burned oil.
now i did blow a seal on my turbine on my ca, but that was revving it at 8grand for 1min runs all afternoon. but it also is from an 88 that has 100+km.
this was recomended to me by my good friends dad who has been a mechanic for 35 years and who had a 190hp pushrod 1.9L n/a mini hemi. A 73 t327 levin. Who was also a head mechanic at a toyota dealership in the late 80’s and also a mechanic for mazda in early 90’s.
my .02$