Well gentlemen I would like to shed a little light on Synlube, I have to admit I succumb to the advertising as well as the descriptive and well versed technical properties purported by the site.
Nonetheless I have held off from posting any info on synlube due to the some of the remarks I might have received. Here is what I can say. I have been an amsoil guy for years and when I had my 98 maxima I took exceptional care of it. At about 36k miles I decided to use synlube, all was going well until I reached about 90k.
During this time I owned a 2004 corolla as well and shortly at around 10k I had installed Synlube, however at around 40k I had some issues whereby the car was bellowing out smoke upon startup no matter what time of the day, I was well started loosing power as well, I tried a lot of things I could think of at the time including changing the plugs.
Interesting to note that I could scrap a layer of dark film or I believe sludge off the oil cap and part of the motor thru the access hole. The problem worsened until I just traded the car in and bought a scion.
Back to my maxima it too shortly after trading the corolla manifested issues very similar bellowing smoke out the tail pipe during startup and also occasionally on the highway and losing power. I called Miro serveral times even shot pics of the spark plugs because I was throwing a code. Now I am really particular in how I take care of my cars and I perform all my repairs, however this was really frustrating.
So I had given Miro and sampling of oil to have analyzed and man did I get the run around that it had to be taken this lab and that this lab was analyzing it for him due to backlog and then he brought it to another lab and had not received any info yet, finally it got lost.
My 98 Max just worsened, I had at this time drained the oil and taken the filter and let that drain over many many many months, all I can describe what went into the drain pan during that time was sludge. However I was religious in keeping it topped up with add oil and changing the oil filter when Miro specified. The last filter was really heavy.
I have had nothing but problems since then in that I was bellowing out smoke constantly, my number one spark plug was getting fouled consistently boy was I upset because I loved and felt I was giving it the best possible (should have stayed with what I knew worked beautifully Amsoil).
At this time I tried to salvage whatever damage was done and manage the situation by piston soaks using kreen and MMO and Lucas occasionally, Lubegard. I finally at this time got the oil usage down considerably (by the way when I did do the front and later rear valve cover all I can describe was a sludge like substance that was still stuck to the valve cover and some areas in the cam bearing caps.
I have been using Valvoline Maxlife thus far and this has considerably slowed the oil consumption, yet I still feel there has been some internal damage yet car is running well. (of note though the dipstick never showed signs of any sludge or varnish anywhere from top to bottom just super clean metal crazy, still to this day)
Now only conclusion I can come to is that using synlube on both cars caused some considerable issue with car bellowing smoke and drivability issues much later during its use.
During 36k to 90k I had used the synlube, since then I have been trying to recover some issues I personally strongly feel it has caused. My vehicle at this point has 162k on it now so far it is doing well, I am just so heightened to any issues stemming from the use of Synlube.
I have been reading this site for last I believe 12 - 13 yrs have not posted anything. I was once a staunch believer in that synlube had something pretty good however my experience with it has not been comforting.
All I can say to those with it synlube just really be in tune the the cars behavior and if you see any build up on the oil cap you may want to take some action.
I followed Miro directions on this synlube to the strictest detail during my use of this oil including his direction on keeping the oil level just above the minimum line on the dipstick, he told me that any more above was not needed so the logic presented was at the time very sound to me given what his oil claimed it accomplished.
Those of you using synlube just really pay attention to your vehicles behavior.
