After searching for the better part of an hour for information on synthetic oils, I came up with little results, other than the fact that Amsoil has blitzed the internet with its marketing. After asking a friend what oil to get and hearing Mobil 1, I wanted to know how its competitors fared against it, namely Red Line Racing's synthetic, the ubiquitous Amsoil, reigning king Mobil 1, and Pennzoil's Syntec. If anybody can provide any concrete, relatively unbiased information, that would be much appreciated.

 

Redline is good oil, but it costs $8 a quart. As for over the counter stuff (Castrol Syntec, Mobil 1, Quaker State....), only Mobil 1 is a "real" synthetic oil made from PAO. Castrol Syntec, when it first came out in the early 90's, were ester based..but now it, along with Valvoline and other $4 or so a quart "synthetics" are actually hydrocracked Group III oil.(highly refined dino oils in a way). I've used mobil 1 5W-30 on my Z. It runs fine. the only thing that bothers me is that Mobil 1 5-30 is on the thin side at higher operating temp, so i am trying the Mobil 1 0W-40 at my next oil change. It should be fine for the Z if it is factory approved from Austin Martins.
As for Amsoil..i have never used it since it is mostly sold through network of dealers, so can't comment on it.

 

I like Royal Purple or Amsoil. I am running Royal Purple at the moment.

 

There is no such thing as 'concrete' info on oil. Ten different "experts" will tell you ten different things. Amsoil really brags their product up. Im an Amsoil dealer, and have listened to all the training tapes, and read all of the books, and Im sure you cant go wrong with it. However, it is expensive, and I dont know for sure if its any better than Mobil 1. I can tell you one thing for sure, theres Mobil 1 in my car...

 

Just changed to Mobil 1 0W-40 yesterday. Somehow the idle seems to be better, but maybe it is just psychological. But i am still weary of the wide point spread and the potential for shearing down. Mobil 1 is suppose to be introduce a 5W-40 (if you look at the Japanese Nismo website, that is the grade of oil they market for 350Z/Fairlady Z33) along with Mobil 1 R.

 

I like the Mobil 1 5W 30. 1st time i changed to this oil I could tell the car was much smoother. A friend uses Amsoil. He says it comes out just as clean as it went in. He also said that Amsoil has a pretty good warranty if you ever have problems. Maybe our Amsoil dealer can clear this up.

 

I am running Amsoil in the crank case, tranny and rear differntial. I have also used Amsoil in my 750+rwhp Supras. Great stuff and have never had a problem with them.

 

I also did a lot of research and ended up with Royal Purple. It's a little more expensive than Mobil 1/Castrol, (I have heard that BOTH of them are no longer true synthetics) but not near as expensive as Amsoil and others. It also tests very well, independant reports rate it higher than Amsoil.

If you're serious, spend a little time and read some of the reports linked on this page. I know, this is from the RP page itself, but some extensive tests were done by NC State University (in my hometown) a respected engineering school and the results were impressive. They ran it in the local Coke distributor's trucks and in the State Highway Patrol cars and did a scientific study. Amsoil was one of the oils they tested it against.

 

check out bobistheoilguy.com, GC (German Castrol 0W-30) seems to be quite popular. and it has some good used oil analysis. The proble is, the only Castrol i can find in Southern California is the "fake synthetic" Syntec

 

I've used only royal purple since the switch from dino oil.
I noticed a difinite smoothness and have no noticeable oil comsumption. I've payed anywhere from $5 to $8 a quart for it.
It's good stuff.

 

rpmoil.com has good RP pricing and for orders >$100 no ship fee.
Still more than the Mobil 1 at Costco though with the tax.

 

Well after much researching and debate, I've decided to go with Redline and see if there's any noticable difference that's worth paying the 6 bucks/qt or so I'm going to shell out for it. With this decision though comes another question, is it worth getting the race oils if I'm only going to drive like a sane man for the majority and like an insane one for the minority; and not the other way around?

 

You can expect a little better mileage (and thus performance) out of synthetic, but only a few percent. What you mainly gain is length of time between changes without harm to the engine. If you're going to change every 3000 miles, you're wasting your $$ with synth (IMHO). With a good synth you can safely go the 7500 miles recommended in the manual (or more if you can stand it, I can't ) without signifigant engine wear.

 

I have used Mobil1 for over 15 years in all of my cars and trucks. I've never had any oil related problems, but I always use the factory oil filter. Used to live in upstate NY where it gets very cold and always felt better about the Mobil1 in the crankcase!

With my Z I switched out the original oil and filter at 1000 miles and put in the Mobil1; then at 2500, then on to a 5000 mile cycle where I change oil & filter every time.

I looked into RedLine's motor oils last year, but I'm reluctant to spend $7/Qt for oil that I have to recycle and filter only to put back into the engine with a new Nissan oil filter.

A few years ago Consumer Reports did a test of motor oils, track that down for some unbiased insight.