...for cars like a 300ZX.

 

Shell Helix Ultra is a fully synthetic oil, Magnatec is only semi-synthetic.

 

In lab tests, Shell Helix Ultra was better than Mobil 1 overall. Both are excellent oils. Testing of these oils in actual cars is underway - I will tell you the results when I know them.

What makes a good oil ?

 

No simple answer. An oil is principally to reduce friction and keep moving metal parts apart. This allows smooth running with low friction, low metal wear. Better oils offer benefits of greater fuel economy, more power, less wear to moving engine parts and reduced build-up of harmful deposits. Also, the oil has to resist premature degradation - this can result in reduced performance benefits mentioned above but also deposits and corrosion.

 

The ideal oil minimises friction, is iso-viscous (same viscosity at different temperatures)-[not currently possible we can only reduce the degree of temperature sensitivity], minimises wear, adequately coats metal surfaces, holds soot and particles in suspension, resists oxidation, resists shear-thinning, etc.

 

Different tests assess different properties, but the best assessment is expensive engine tests in real-world driving conditions.

hi,

it just depends on how you test the oil and what you feel is important,,

also it depends how good its filtered,you can have the best oil in the world and put on a shite filter and you'll fook an engine just as quick as shite oil!!!!!

also fully synthetic is not suitable for all engines!!!!

hi,

dontcha just love double posts!!!!!!!!

 

[This message has been edited by neil (edited 29-08-2002).]

Most high performance/new engines are designed to be used with fully synthetic oils. Older engines are usually better with semi-synthetic or mineral oils. This is because fully syth oils are usually significantly thinner to allow greater fuel economy and power. If the engine is not designed for the thinner oils then use of them can cause problems. The thin oil may not result in thick enough oil films and poor lubrication in the wrong engine.

 

Oil filters are pretty crude -they only filter out relatively large pieces (20 micron or less) of metal. Obviously they are important too.

 

Waht's important are 3 key things - engine wear, performance and oil longevity.

ello,

you keep bragging off shell,,well thats your baby..but be very careful,,

out of personal experience it's not as(high temp) stable as other oils available on the market,which is not good on high output engine

Not saying that my dad is bigger than your dad,just don't force it down everybody neck[please]

and to answer your original post,i should hope it is. As the two oils are designed for totally different markets......

 

also anyone using magnatec in there 300,some simple words of advice...BUY SOME BETTER OIL

I'm trying to help people make the best, most informed choice, NOT trying to "force it down people's throats" !!

Some people asked for more info. so I am giving it. I said Mobil 1 is also excellent oil, I am trying to be objective and fair.

 

Why do you think it's not as high temp. stable as other oils ? What other oils ?

 

Oils can be compared - it's not a subjective thing of 'I like this one, you like that' !!

 

An oil is either better or worse than another.

ok,

the best oils are available over the pond!!(amsol,millers)but a really good english oil easily on par with helix,mobil 1,castrol..is morris,,not heard of them??

the best adative to any oil is (own experience and most of the other teams racing in fixed engine catagories)extralube zx1 this stuff is unbelievable(vauxhall 2.0 16v non ecotec engine 7bhp just by add the bottle????sounds good to me)

--hth--

--neil--

not being nasty but...

 

I thought American oils were crap like most of their cars..big lazy 2-valves per cylinder gas guzzlers. American way is to change oil often (~5000 kms) - so oils don't need to resist degradation as much as oils made in UK.

 

The Chevy Corvette is a great car, but not as good as a 300ZX TT in terms of overall performance.

a recently released caddilac has it's first service at 100,000miles(this is no bullshit)it can also run without water to get you home

also you need one really good oil to hold 8litres,8500rpm,1300hp together(not the same car!!)

it's not really going to affect most people on here which oil they use(talking synthetic's)but after 550-600hp in one of these engines you'll have to be oil critical,

but you only find how good an oil is when things go wrong i.e oil temp rises to crazy levels,most cars only run around 90 degrees c maybe 100 degrees on a flat out run! but start to increase that to 150-160degrees and see how many oils are still together??

not many

also not saying that mobil 1 will hold together either,

it's nice to know though if for any reason something should go ape! you're oil can cope!

 

--neil--

which oils CAN cope at 150-160 degC ?

amsoil severe racing oils

also any oil with extralube zx1 told you its good stuff!!

 

--neil--

On a side note:

The oiltemp in a mildly tuned Zed (chip/exhaust/intake) runs at about 90-125 degrees Celcius.

 

I recently installed a new and bigger oilcooler in my car and it's something I can recommend to everyone...it can make a difference of 15 degrees Celcius on hot days.

 

The stock oilcooler on the J-specs and US-specs Zeds is too small to cool the oil once it gets over 110 degrees Celcius and can lead to serious problems on hot days.

The UK/EURO-specs already have a larger cooler, so these cars don't have this problem that much.

 

Also make sure the oilcooler circuit isn't blocked...since this is a common problem on Zeds as well.

The cooler should already be really hot when the engine is running for 5 minutes.

If it isn't even warm or just the line to the cooler is hot: it's probably blocked or the oilpressure is (too) low.

 

-Eric

 

[This message has been edited by lymon (edited 30-08-2002).]

So, for us Jap Zed owners, we need to steal an oil cooler from a UK spec car and just swap them over eh?

 

Sounds like a plan?

 

I understand Luke is soon going to [soon] offer an alternative oil cooler system that requires you to: Add a new cooler unit, re-plumb your current engine oil cooler circuit to it: then re-plumb your current gearbox oil cooler to the now redundant engine oil cooler. Killing two birds with one stone. Does this sound like a good plan?

 

AndyGP

Lymon

 

Quote "Also make sure the oilcooler circuit isn't blocked...since this is a common problem on Zeds as well.

The cooler should already be really hot when the engine is running for 5 minutes.

If it isn't even warm or just the line to the cooler is hot: it's probably blocked or the oilpressure is (too) low. "

 

 

You sure about this. My UK oil cooler stays cool unless I really use the performance on a warm day. Then I can feel it get hot otherwise it stays cool. I thought there was an oil thermostat that only let oil circulate when very hot. It would be a bad thing to chill cold oil so there has to be a stat?

Willie

Yes, I'm sure about this.

Also a common misconception about the Zed's oilcoolsystem is that it's regulated by a thermostat, which is NOT true !

It's pressure regulated, the oil starts flowing through the cooler as soon as the oilpressure hits ~4 bar.

..so it runs always, especially when the engine/oil is still cold but oilpressure is high.

(I'm not sure why Nissan decided to do it this way)

 

My old cooler also stayed cool, unless I really stepped on it.

I "cleaned" the 2 little pressure valves that are located in the bracket where the oilfilter connects to and since then the oilcooler always gets hot.

 

[This message has been edited by lymon (edited 30-08-2002).]

Originally posted by lymon:

My old cooler also stayed cool, unless I really stepped on it.

I "cleaned" the 2 little pressure valves that are located in the bracket where the oilfilter connects to and since then the oilcooler always gets hot.

 

[This message has been edited by lymon (edited 30-08-2002).]

 

Easy answer Eric - you broke the spring behind the pressure valves when you "cleaned" them LOL

 

CheerZ,

 

Andy

neil -severe racing oils are probably fine for track use/racing but not the best oils for an everyday road 300ZXTT.

 

BUT it dpeneds what you want out of the car - more power/more reliability/less engine wear. Sometimes these factors are mutually exclusive to some extent.

OK, but which is the best oil to use? I am about to change my oil and want to make the right choice first time. Jap TT auto 1993 standard at the mo. Please.

ok, im gonna stick my neck out on this one!!

 

mark - ANY good quality synthetic (if you want to pay the extra) or, heaven forbid, semi synthetic oil will be fine for most people for normal road use. even driving hard.

 

if your gonna do oil changes every 3000 miles, as many of us do, then your not really gonna get the benefits of a fully synth oil which is designed to last many times more.

 

my personal recommendation is Mobil Super S. its a very good quality semi synthetic oil that isnt over expensive. we use it everyday in my merc workshop, in supercharged engines, turbo deisels, & dirty great 5.5l V8 amgs, these do up to 20,000 miles between servicing without problems, many have 250k miles on the clock & still going strong.

 

just my experience in the real world - try to read through marketing hype!!

 

------------------

I feel the need, the need for speed!

 

 

[This message has been edited by Paul C (edited 01-09-2002).]

Originally posted by Nelson MainFella:

Oil filters are pretty crude -they only filter out relatively large pieces (20 micron or less) of metal. Obviously they are important too.

 

Presumably you mean 20 microns or more ? But I understand that there is a big difference between different oil filter manufacturers.

 

You refer in your initial post above to Castrol Magnatec but I think the original discussion was comparing Shell synthetic with Castrol synthetic. How does Castrol synthetic compare since I know it is commonly used by a lot of people with Zs ?

 

Dave

20 microns or less - I meant some filters are finer than 20 microns -I've heard of 5 microm ones.

 

I don't know how Shell compares with Castrol in fully synthetic forms. Will try and find out.

 

Fully synth oils do last a lot longer than other oils, but if you change your oil every 3,000 miles, that's not very important. Fully synth oils have performance benefits like better fuel economy, more power, engine cleaning. How BIG these advantages are, it's hard to say. I'll do more research.

 

i referres to Magnatec becasue that's what a few people said they used, and they thought it was the best.