Ive been using castrol syntec 5w-20 since i got the car at 21k miles and the previous owner used all sytec as well. However, my car is reaching 60k miles (damn 04 3i 2.0L and the previous owner driving to cali and back from St. Louis like 3 times) and ive been leaning more towards the castrol syntec blend 5-20. I want to throw in some hi milage to recondition the seals and what not but im probably having my heads ported and polished soon with a bored out Throttle body and while im helping with the headwork ill probably starting replacing seals anyway. but ill let you guys know how that works

 

There are those who believe that pure synthetic is great in engineering tests, but that not having some "real" oil as part of the make up somehow deprives the lubricant of something which should be there.

I have known several mechanics over the years, none of them used synthetic oil in their personal cars. They were more adamant about getting the oil and filter changed a little more quickly than manufacturers recommendations, than they were all hung up on brand or synthetic. One guy I knew changed it as soon as he saw any change in color on the dipstick, since he saiddiscoloration was dirt, and he wanted dirt out of his engine.

Semi synthetic oil could be worth considering ... maybe the best of all worlds?

 

When I purchased my MS3 (still waiting for delivery) I spent some time talking to the parts manage who owned an RX8 and ran synthetic oil in it. He said that it wasn't recommended by the manufacture, but the only difference he, and the others he knew, had noticed was a slight increase in oil consumption. I don't know much about the rotary engine, but I think they tend to consume more oil and it is likely that the manufacture knows people will consider the "extra" consumption abnormal.

 

I'm willing to bet the majority of the mechanics you know are the"older generation" and don't like change very much. I'm not knocking them,it just seems to be the case. Personally, I believe the science that synthetic is better, but the best feature it offers is resistence to high temperatures. This means added protection if there is a failure in the cooling system. If you change your oil often enough it really doesn't matter what you put in it. I know a guy that ran a Bronco over 300,000 miles on Pennzoil conventional (which is considered to be about the worst oil by many), but he changes his oil ever 2,000 miles. The synthetic oils allow a longer change interval because they are more pure and don't break down as quickly.

If you do some research, you will find that there are three groups of synthetics.Most synthetics are really purified/modified petrolium oil that originated in the ground and are Group 3 Synthetics. Mobil 1, Royal Purple and AMSoilcome from the lab and are Group 4 synthetics. I'm not positive, but I think all of them use PAOs for the base oil (I know this is true for Mobil 1). Redline is the only Group 5 synthetic that I know of and it use Poly Esters (?) as the base. Group 5 is generally the category for additives. Also, the synthetics use less additives because they can build the properties into the base products. I'm no expert, I have just some some reading. The Group 3 oils are only considered to be synthetic because Castrol won in court when Mobil 1 sued them. I generally use Mobil 1 simply because it is easy to get andthe price isn't horrible. AMSoil, Royal Purple and Redline are more difficult to obtain.

 

okay, im due for my first oil change sometime soon (im at 4500kms)...
what are the advantages of synthetic oil over plain old oil??

i drive a mazda 3 with the 2.0 engine, btw

 

(1) I think you can comfortable run syntetics longer between oil changes. In my Tundra I went 7,500 miles (mostly highway miles, some with a small trailer) without discoloration. I generally changed it at 5,000 miles.

(2) There is less friction with synthetics so in theory the engine should last longer, but if you are not planning to keep the car beyond 100,000 miles it shouldn't be a factor for you.

(3) Because it hold up better to heat, it provides some added protection if you have a cooling system issue.There is a guy on one of the Toyota boards that I'm on that tried to toast his motor before he installed the new one. He pulled the drain plug anddrained all the oil. He drove it over a 100 miles with the remaining Mobil 1 and the engine was still running fine. He won't run anything else.

(4) You might see a slight increase in gas mileage.

(5) In the cars that I have switched to either synthetic or blend I have noticed the engines felt smoother and quieter.

(7) Synthetics generally have better detergent properties so they keep your engine cleaner. This is part of the reason that high mileage engines develop leak when switched. The synthetic oil cleans out the build-ups that were covering leaks.

If you change your oil on a regular basis, you may never notice a significant differenceand it does cost a bit more.

Iam currently planning to run Mobil 1 in my new 89 4Runner engine once it gets put together and broken in and the MS3 will either have the dealer synthetic (Quaker State) or the Redline they offer in the parts department. The Redline is overkill for most cars, but since it will be going through the turbo it might be a good investment for me.

 

ive put on 4500 km's on my mazda in the past 5 months, so the price difference really isnt a big issue...
and i used to drive an '89 4runner...
until this happened.....



i hope that pic worked....

 

dammit.....the pic wont load cuz its a .bmp or whatever, and mazdaforum doesnt support it....

 

im gonna end this stupid argument once and for all.

u guys should realize. that using full synthetic is CHEAPER than regular oil. not only that, it will make ur engine last ALOT longer. if nothing else breaks, 200k+miles isnt unheard of for a car on Mobil1, etc.

cheaper, why? because regular oil u shud change ever 3500 miles. with my Mobil1 5W-30, i do a change every 7500. thats double the mileage, and slightly less than double the cost. (i get 5 quarts for $23 @ walmart)

if u dont run synthetic ur being retarded to ur wallet, and ur car.

 

time to put that to the test

HAHA YEA RIGHT. thats total bull**** IMO.