Thread: Oils ain't oils . . .

Cheers rick, I have never really looked into oil as much as now, I thought viscosity was all i needed to know.

Is there a lot more to protectant additives than just levels of zinc? Also, what should I be looking for to get an idea of detergent levels in an oil? Are some detergent additives better than others?

Originally Posted by series3

Cheers rick, I have never really looked into oil as much as now, I thought viscosity was all i needed to know.

Is there a lot more to protectant additives than just levels of zinc? Also, what should I be looking for to get an idea of detergent levels in an oil? Are some detergent additives better than others?

Most of the organo-metallic additives used are synergistic, ie. they work together and often have dual roles in a blend.
ZDDP is/was widely used as an anti-wear additive as it was relatively cheap and just plain worked almost better than anything else, and if you had a particularly tough environment just tip some more in, (unlike a lot of things) but yes, there are a number of good anti-wear additives that are probably better than ZDDP, but are quite a bit more expensive for a blender too.
An example of something better from over twenty years ago is Lead.
Lead napthalate was sometimes used in some boutique ($$$) blends and was probably a more effective additive than ZDDP, but there are obvious health implications with it, and it was very expensive.

An example of a more recent additive is some of the Boron based additives which are often used in a few synthetic oils to replace ZDDP, particularly the heavy duty diesel oils as they are very effective. A side effect is they don't poison catalytic converters so can be used in dual rated/fleet blends.
Chevron/Texaco/Caltex has a range of conventional (mineral) gear/diff oils that use a Borate based additive package (they hold the patent on it) that rivals some of the best synthetic gear oils in performance.
Tin Napthalate is starting to be used by some boutique blenders ATM to overcome problems they are having with E10 and higher levels of ethanol and direct injection petrol engines (fuel dilution)

Calcium is one anti-wear/detergent additive preferred by Japanese diesel engine builders.
Most Japanese diesel manufacturers specify an oil with >3000PPM of organo-metallic calcium for it's anti-wear and detergency characteristics in their engines.

As far as detergency goes, like anything else it's a compromise/juggling act to fit as much 'stuff' in your brew and still lubricate what you are trying to lubricate, but most all your diesel oils obviously have better detergency levels than a respective petrol engine oil and usually have an overall beefier additive package, and quite a few are dual rated to the latest petrol oil specs too, eg CI-4/SL or CJ-4/SM

The petrol engine oils dual rated, say SL/CF are pretty good for detergency, CF was the peak diesel rating from only about fifteen years ago and these are often the recommended oils for the modern, common rail light diesels.
Having said that, heavy duty diesel oils have moved on a long way since then, but it shows how good some of the current petrol engine oils can be in terms of diesel performance.

BTW, good luck trying to find out what a blender uses in their oils, (although they often let one or two snippets slip for the advertising fella's) it's a bigger trade secret than any Chinese State secret.

Cheers Rick, a lot of info to digest there! It should put me in the right direction though.

Are there any more pitfalls in considering these modern, diesel/petrol oils in a 2.25 (especially one with <10,000km)?

Do diesels demand better lubricants than petrol?

Time for some hunting!

EDIT - I have found some diesel oils with the right viscosity levels that have been noted to have high (>3000ppm) of calcium. I think this would be a good oil for me, because my engine is low km's so will still be clean inside . This oil will keep things that way. Some opinions I have come across worry that using a high-detergent oil in a high-km motor can possibly cause problems in itself, but this doesn't concern me.

Also, my case is a bit unique as my petrol motor runs diesel pistons, rings and gudgeons etc.

Originally Posted by series3

[snip]

Do diesels demand better lubricants than petrol?

generally, yes !
Diesel engine oils usually have a much more robust additive package, I know of one industry insider that runs Delavc 1 (Mobil's top of the line, full synthetic diesel oil) in his Boxster, with the blessing of Porsche Germany

EDIT - I have found some diesel oils with the right viscosity levels that have been noted to have high (>3000ppm) of calcium. I think this would be a good oil for me, because my engine is low km's so will still be clean inside . This oil will keep things that way. Some opinions I have come across worry that using a high-detergent oil in a high-km motor can possibly cause problems in itself, but this doesn't concern me.

Also, my case is a bit unique as my petrol motor runs diesel pistons, rings and gudgeons etc.

I was only using the calcium as an example of the dual roles played by the additives and the specific requirements for Japanese engines.

I'd just select an oil that had good/recent approvals and was easily available and you can get a good deal on it.
eg. i can get Fuchs Titan Ultralube 15W-40 easily and cheaply, so use that in the tractor and Dad's Falcon.
Interestingly the 4.0 litre stopped using oil when I swapped over from whatever bulk oil his mechanic had been filling it with.

re the calcium, I ran Delvac 1 for years in a Nissan TD42T, one engine in particular that the manufacturer required high calcium levels and D1 'only' has something like 2500PPM calcium and the results were brilliant, but the majors know how to blend an oil without relying on just one additive to do the job.
Caltex had a huge barney with Nissan over the high calcium requirement and ended up running their entire fleet of Japanese utes on Delo 400 (which gave stellar results) to prove to Nissan they didn't require the 'crutch' of high calcium #'s these days but the Japanese were unmoved.
There's a reason why they needed >3000PPm calcium back in the eighties, but i'd bore you to tears with the ins and outs.

Originally Posted by series3

Cheers Rick, a lot of info to digest there! It should put me in the right direction though.

Are there any more pitfalls in considering these modern, diesel/petrol oils in a 2.25 (especially one with <10,000km)?

Do diesels demand better lubricants than petrol?

Time for some hunting!

EDIT - I have found some diesel oils with the right viscosity levels that have been noted to have high (>3000ppm) of calcium. I think this would be a good oil for me, because my engine is low km's so will still be clean inside . This oil will keep things that way. Some opinions I have come across worry that using a high-detergent oil in a high-km motor can possibly cause problems in itself, but this doesn't concern me.

Also, my case is a bit unique as my petrol motor runs diesel pistons, rings and gudgeons etc.

Can you tell me more of the benefits of diesel pistons in a petrol. Sounds interesting.

There aren't really any noticable benefits to using diesel pistons etc.. but no noticable drawbacks either. The motor still needs to do at least another 10,000km until it's fully loosened up.

The diesel pistons are heavier, as well are the gudgeons and conrods. Hypothetically, the engine will be less willing to rev, but hopefully will also be less willing to sacrifice revs when put under load. Time will tell....

Also, back on the oil situation, I am 90% sure of getting Penrite diesel HPR 15 (15-50) but not sure yet.

Originally Posted by series3

There aren't really any noticable benefits to using diesel pistons etc.. but no noticable drawbacks either. The motor still needs to do at least another 10,000km until it's fully loosened up.

The diesel pistons are heavier, as well are the gudgeons and conrods. Hypothetically, the engine will be less willing to rev, but hopefully will also be less willing to sacrifice revs when put under load. Time will tell....

Also, back on the oil situation, I am 90% sure of getting Penrite diesel HPR 15 (15-50) but not sure yet.

Did you fit the diesel flywheel as well??? That would make the greatest difference to torque down low - as it is quite a bit heavier...

Nope, only did the motor itself