most everything i have found by searching is about synthetics. i dont want to go synthetic. what do you guys reccommend? i used the high mileage pennzoil in my z31. i have seen Mobil non-synthetics, and know that mobil is a respected brand. also, anyone use K&N oil filters? or should i just get the nissan filter.

 

syntec blend imo

i use the K&N filters, expensive, but no cardboard

 

Might I ask why not synthetic? It's superior in every aspect to regular oil except in price. On top of its superior properties its synthetic, which means that less crude goes toward motor oil. Which means that more goes into fuel I think non synthetic motor oil should have it's production halted. We obviously have superior alternatives to it. The less we depend on crude oil the less it's going to cost for other things like gasoline .

 

I've gotten from 250k to 370k miles out of a few cars, on original engines, using good old plain Pennzoil & Castrol GTX. I started using STP after about 150k miles in all of them. I even put Slick50 in all but one of them.

The Z only gets Mobil1. I'm even kind of leary about going against my tried and true processes, but only time will tell.

 

There was a thread a few months ago that went into alot of detail about what oil to use. I can't find it or I would post a link to it but we came to conclued that if you don't use synthetic and change your oil between every 2,000-2,500 (like I do) it would be the equivalent of running synthetic. I donno what to believe but there was good evadence to support both sides of the argument between useing synthetic or just regualr oil. I use castrol GTX high milage and try to change my oil every 2,000 miles. Some people call me crazy but that just my way of assuring myself my car will last a long time.

 

Regular oil will do the job just fine. I'm not disputing that. I just like the idea of not using 'real' oil to do it. Think about it, if we no longer used crude oil to make motor oil that would take a HUGE strain off of the supply. We NEED that petro to make gasoline. There's no way around it (not yet anyways). But we obviously dont need it to make motor oil. We all complain about gas prices and what not but every time we use standard motor oil it's not helping the isssue. There is a lot machinery that uses a lot of oil and if everything ran with synthetic think of how much crude that would save There are over 600,000,000 passenger vechicles on the road in the world today. Now if each car was driven 12000 miles a year and changed their oil every 3000 miles and used an average of 5 quarts that would come to a total consumption of 3 BILLION gallons a year. Thats not counting commercial and fleet vehicles or the marine and aerospace vechicles that rely on oil lubricated propulsion (and generally use more than a passenger vehicle). Thats a whole lot of oil. It's starting to sound like I'm preaching now so I'll quit and let this thread get back on track

 

You make a really good point. I never thought of it that way. Makes me want to buy synthetic now (not kidding).

 

unfortunately, your argument does not work. crude oil consists of many different hydrocarbon chains, each of which are used for different things. the chains used for gasoline are different from the ones used for lubricating oil. if we stopped using lubricating oil derived from crude, it would just become a waste product of the refining process.

here is a link with a nice visual aid to explain this http://science.howstuffworks.com/oil-refining2.htm

the reason i dont want to use synthetic is that i am worried about the potential for leaks. i dont care about the cost, and i change it every 3k no matter what. is the leak thing something i should be concerned about on a car with 87k?

 

LOLzzzz..... I was gonna post up the same link for the motor oil / fuel discussion.

 

So I can assume High Mileage Castrol GTX is a synthetic oil? Why would more leaks come about from synthetic as opposed to regular?

 

Ahh, but see the longer hydrocarbon chain of motor oil can be broken down into a smaller chained gasoline by chemically altering the chain. So either way you look at it making motor oil is wasting a resource for other materials. If you read into the column a little more it even explains that this is done since not nearly enough gasoline is yielded from each barrel of crude. More gasoline gets used than anything else so refineries will chemically alter other fractions to make gasoline.

 

And to answer Entropy's question about leaking. Here's the deal with synthetics. They get their bad rep from the fact that they lubricate and protect so well. No joke. Thats what it comes from. Cause boneheads like GM liked to use synthetics like Mobil 1 to break in motors like that in the Corvette. Problem is that these oils do their job so well that the motors dont have a chance to break in. So things like rings never seating happen and the car is doomed to burn oil until they eventually seat after 60,000 miles of synthetic. Conventional oil is ideal for breaking in a motor. But once that phase is over there are NO drawbacks to a synthetic motor oil. It's not any more susceptible to leaks than conventional. Viscosity is viscosity.

 

i believe not all of the hydrocarbons can be broken down into gasoline. the fuel oil ones can, i.e. heavy fuel oil, diesel fuel, kerosene etc. but i dont think the ones used for lube oil can. i'm not 100% on this, so anyone correct me if i'm wrong.

and i didnt mean oil blowing by the rings. i was talking about the effect synthetics can have on seals. i've heard they can harden seals, and can clean the seals too much, opening up new leaks.

 

I dont know, it was just a thought. I'm no chemist

 

If Mobil 1 is good enough for Porsche and Astin Martin, it is good enough for me.

 

Entropy, all motor oils, whether standard, synthetic, or a combination of the two, have to meet certain standards. And their effect on engine seals is one of the standards they have to meet. So I doubt synthetics would be able to degrade a seal any noticeable amount faster than traditional motor oil and still be able to meet those standards. Plus no two synthetic blends are the same. Mobil 1 for instance has patents on it's formula.

 

Probably the best non-synthetic motor oil is the Castrol GTX product. I've seen numerous tests where it was the only standard oil that didn't start breaking down after 3,000 miles.
Synthetics provide superior lubrication and better protection against wear. The leaks people have blamed them for were cases where the synthetic was used in high mileage engines. It dissolved all the built up gunk inside the engine which resulted in leaks and increased oil consumption. One thing that neither synthetics, nor filter changes, will protect the engine from is acid build-ups form condensation resulting from ambient temperature changes, improper A/F ratios, etc. That is why they still recommend changing oil at least once per year.

 

i just went synthetic, no leaks have popped up. car runs better in my personal opinion. my lsd was slipping alot so i changed the rear diff to synthetic lsd gear oil. and yeah im griving the car nicely to break it all in, also cuase im running straight pipes right now till i feel like attatching my mufflers and its really freakin loud so i try to keep the revs down to avoid the loval PD.