I have Proline 10W-40 in my engine today.(cost 5$/quart) But for next oil-change:

I discovered that a local store sell Mobil 1 as an offer for 65$ for a 0,9 gallon (ordinary price: 116$ / 110$)

They offer 2 types:

Mobil 1 SuperSyn: 0W-40 "Protection Formula"

Mobil 1 SuperSyn: 15W-50 "Rally Formula"

But witch one is best for my engine (and me)? I dont use car in winterconditions. The lowest outside temp: 35*F , and highest: 88*F. Mainly between 50*F and 77*F.

Engine: 305 LG4, RPM intake + RPM cams, Edelbrock 1405 600cfm, no emission-controlsystems/no catalytic converter. Sportexhaust, comp ca 9,3. Octane 95, sometimes 98. No oil-leaks. Drive about 4000 miles pr year. Runs great.

Priorities: Power/Hp, engine protection/clean, fuel- and oil efficiency (in that order).

I have read many threads about Mobil 1, but no one mention grade 0W-40 (that we have here in Europe)

Comments, recommendings?

 

15w 50w,you dont get real cold temps to need the 0w,and you get the hot temps protection of the 50w 0.02

 

I read good things about Mobil-1 0W-40 on bobistheoilguy.com so I've been using it in my wife's Land Rover. The engine is quieter during warmup than it was with Castrol Syntec 5W-50 so I'm assuming it likes it.

This oil does well in LS1 engines in terms of wear metal content, so it may be a good choice for what you're doing.

 

the only thing i'd be concerned about with 0w oil is it's ability to carry metal particles and dirt to the filter. Yes it's used on current foreign cars but those engines weren't designed in the 70 and prior and the oil passages are probably built for low weight oil where as back in the day, there was no synthetic and our 305/350's were built assuming you needed a high weight oil so it would lubricate at high temp etc etc. Maybe there isn't a difference when it comes down to it.

 

Check the site I posted earlier, a few LT1 engines (reverse coolant flow regular Chevy smallblock) running Syntec 0W-30 and whatnot with great wear metal results.

And here's something to consider...at 200degF or whatever you run at, a 0W-30 is the same viscosity as a 10W-30. Check the specs on your favorite oils, they publish two numbers you're interested in...one at the std low temp, and one at the std high temp.

 

I use 5w30 full synthetic. The difference isn't all that much between 5w and 0w. I was only guessing at a possible reason to not use 0w instead of the recommended 5w. Whatever oil you end up using, as long as it's synthetic it's probably fine.

 

The recommended oil viscosity for the engine is 5W-30 or 10W-30. Since neither of those is offered to you locally, the closest to that is the 0W-40.

The 15W-50 is really thicker than you need. It won't protect any better, but it will make the engine work slightly harder.

 

Unless your engine was built using looser tolerances stay away from the heavier weight oils if they're not needed. like 5-7 said makes the motor work harder and takes away hp. That trend of running 20-50W or straight 50w is 70's technology at it's best.

With a properly built motor-even high hp ones now use typical 5-30 or 10-30 oil or stright weight 30W oil. That 0-40W will work just fine provided the motor was not built with looser than factory specs.

I did notice when I switched from 10-30W systhetic to 5-30W synthetic i lost about 5psi of oil pressure at start up, but once motor is upto temp it ends up the same. I'm also a fan of running Lucas oil stabilizer. I've always run the tradidtional stabilizer, until they came out with the synthetic version. Tried that for 1 oil change and lost 10psi, so went back with the traditional Lucas NON sythentic version. Also run some in my diff as well.

 

Thanks everyone.

I did know the different characteristics between those two oils but was doubtful about this (old) engine construction, and proper oilgrade for it.

I presumed that the engine would prefer higher grade/thicker oil because of its relative rude construction. But using lower oilgrade, if techical possible (like that 0W-40), it could profit of lower inner friction.

But what is GM oil-spescification for this engine? Doesnt it say 15W-40 and higher!(?) ......in mineraloil grade....yeah...i know...With syntetic oils we can choose lower grades.

I know that 0W-40 at 60*F is dripping like water...but oilpressure will be high enough for the engine at my temp.range?

My thermostat is a 195* (just changed)
At my knowlegde, engine also is in good shape.

 

castrol's synthetic though isn't the greatest out there

not even really a synthetic due to the base stock
mobil 1 tends to be quite a bit better

 

as far as the lucas stuff
checkout
bobistheoilguy.com
they did some stuff with that using a little gear drive system

the lucas stuff did a good job at trapping lots of air inside the oil which isn't the greatest thing for gears

 

When I pulled the old motor out, I ran lucas in that as well. I did'nt do a complete break down sincei was selling it, but after 2 seasons of racing plus many many street miles the few mains and rods I pulled off showed bearings that still appeared new. So bolted it back together and the new guy is still running it-strong as ever.

I wont get into an arguement, I've heard stories both ways on Lucas some swear it's the greatest thing since the light bulb while others say it's like a time bomb. As normal for the auto industry to have findings/debates on both sides. I'm really impressed with what it did with my first motor so I will continue to run it until I've seen first hand any damages to my stuff or the many other guys I know running it in daily drivers and their race cars.

A little fun experiment I did on rear end # 2 or 3-cant remember, anyways I was missing 11 teeth on the ring gear and it made the most awful howl you've ever heard from a rear end. For fun, I put the cover back on and filled completely with Lucas and took it for a spin. That drive was the quietest I could remember in the car it literally took out all the nosie from the rear LOL.

 

Look on the back of your bottles....i work at an autoparts store and in july they raised the standard of oil from GF-3 to GF-4 and the only synthetic out of mobil, valvoline, havoline , and castrol that meets GF-4 is castrol syntec

 

All that means is they began shipping containers so marked before the others. Or, that they got their certification through earlier. It doesn't necessarily mean their oil is better, or that the others wouldn't meet the GF-4 standard.

The requirement isn't mandatory until May 1, 2005. API SL is all you'll see in owner's manuals (Edit - and the "starburst" in 1993-newer).

 

Here's a good thread on synthetic oil and visocity, very informative. kinda long but worth the read IMO. Too bad it's on a M*ustang site.

http://www.boss302.com/board/viewthr...7&pagenumber=1

 

Don't bother. That "cobravenom71" guy, who posted the greatest volume of the "technical" discussion, is only right on about half of what he says.

Besides, the originator only has a few choices available to him. Most of this discussion doesn't do him any good.

 

Is he right about AMSOIL just being Mobil base w/ lots of additives?

 

Absolute rubbish.

 

So 5-7, why don't you clue us in on what exactly is true and what's false? I've read that thread a few times and a lot of the stuff he said seems to make sense. I'd hate to go around believing something that is inaccurate.

 

but just because it meets a standard doesn't mean much unless you know what the difference between the standards is

and just becuase it doesn't meet that standard doesn't mean it isn't good oil or better sometiems for a situation


like my car in the tranny good luck getting me to run gl5
I wil choose the "lower" standard being I like my synchros and gl5 isn't going to be a happy mix from my understanding

 

5-7 I have heard that amsoil out of all the syn oils has the highest amount of addatives in there. is that true?


but can I get your opinion atleast on castrol.
good dino juice but as far as the base stock fo syntec goes it isn't the greatest and mainly is just a high refriend dino juice rather then a true synthetic correct? anything else you would like to add

 

amsoil increases viscosity 10-15 weight as it ages in use to 18,000 miles. It still provides excellent wear protection to that point, but in cars that will have trouble with a higher weight oil, it's not the one to pick. Mobil 1 on the other hand can do the 18,000 mile leg without increases in viscosity. There is a comprehensive wear test on some site labratory testing the oil every 1000 miles.

 

have you guys seen this article?
http://www.carcraft.com/techarticles/15378/index.html

 

Where exactly is that site? Truth: AMSOIL maintains its viscosity with age as well as or better than anybody else's similarly rated viscosity oil.

That article is a little old (mentions "SJ" rated oil), but is much more technically correct than the 'stang site. For instance, it properly identifies what causes sludge with petroleum-based oils.

I'm not going to hijack this thread and spend the time to do that. Go to the above-linked article and www.amsoil.com and read your heart out.

One other little "detail": The VI improver additives function to thicken an oil at high temperatures that is thin at low temperatures. A good synthetic base will need little or no of these VI additives to achieve both the "W" rating and the straight rating. Petroleum oils use a lot more, typically, although Castrol came out with a 5W50 synthetic that had more than the typical petroleum 10W40 oil. These VI polymers are typically the first thing to "break down" or oxidize under heat and shear, at which point they make the oil even thicker. I honestly don't know whether the M1 0W-40 has more or less VI improver than the 15W-50, but I would guess, as is usually the case, that the higher spread has the higher amount of it.

Oh, there are different qualities of VI improvers out there; the "major" synthetic manufacturers tend to use the higher quality products, even though they also use less of them. The major petroleum oil suppliers tend to use the lower quality additives, even in their wannabe synthetics.

 

recommending to read the companies own site to see how great their oil is, is just plain foolish. Every companies product is the best product in the world.

You want a real independent test. http://neptune.spacebears.com/cars/s.../oil-life.html

There, you read your heart out. That is as independent and thorough of a test you'll ever find anywhere. At 40 dollars every 1000 miles, you see why nobody else has done this.

And no, amsoil doesn't maintain it's viscosity, it actually went from 5w30 to 5w40 and climbed even higher while Mobil 1 did not. More oils are to be tested but with a single brand taking about a year to test, it will be a little while before preliminary results are in.

 

Good site, but if your point was that Mobil-1 is better than Amsoil you might want to look at the comparative wear metal data...the Mobil-1 samples were carrying much more metal than the Amsoil ones.

 

No, if i wanted to say mobil 1 was better, I would have said it. I only said what i repeated, amsoil increases in viscosity. By the way, if you read the entire thing, mobil 1 was tested first and it was on a newer engine, the high metal wear could have been due to the breakin period of the engine. They are retesting mobil 1 for the first few thousand miles to see if it shows any different data.

Depending on the outcome of the retest (to take away doubts of breakin period) will determine which oil is better.

ps, i'm actually more interested in the results from castrol syntec and others... since i dont use amsoil or mobil 1 personally.