Here is the link to this famous article that is supposed to prove that (at least some) oil additives are bad:
http://www.bobistheoilguy.com/images/lucas/lucas.htm
I found this article very informative but I have a few remarks/questions about it:
1) In the beginning one compares a 80W90 blend with a 80W140 full synthetic. Prior to any additivation, one can see that the full synthetic climbs the gear much less than the blend. Even if the temperature is the same for both oil, the viscosity of the SAE140 is much greater than the one of a SAE90 grade so this comparison is not fair. That's not the point of the article of course but IMHO it would have been better to compare similar grades. The very best would have been to compare the same oil: once with additive and once without the additive...
2) The third pic shows that the full synthetic Pennzoil is getting white even prior to adding the Lucas additive!! So the Pennzoil is foaming a lot by itself and without any additional additive. Foaming is hence not caused by the Lucas additive but there is another thing going on here.
3) Adding Lucas makes the oil climb the gears but also turns the oil white. This means even more trapped air......or that the additive itself is white! Being in Europe I have no idea about the color of the additive. Can anyone tell if the additive is clear or dark by itself? If yes that may explain the light color. I mean I'm using MoS2 additive in my gearoil and without surprise the oil turns black! However this doesn't mean the oil is contaminated or that there is sludge dissolving in the box...
4) If foaming is indeed causing this white color, shouldn't we see a color difference between oil in movement and oil settling down in the pan? Obviously foaming occurs when gears are moving and oil is sprayed everywhere. After settling down for a while, some of the foam would dissappear and the oil should gradually turn back to its original color. A good test would have been to take a pic after 10min settling in the pan. If the oil was still white at the time, it would mean that Lucas additive, if not white itself, is turning the oil white but this would have nothing to do with foaming. Again think about Moly turning any oil black...
5) After all the Schaeffers 267 contains moly right? Is that really a fair choice for color comparison with other oils? After all, does a moly oil turns white when it foams?? I guess no....but it doesn't mean it is not foaming. Taking moly oils as a reference is IMHO the biggest mistake in this article.
I'd be glad to have your expert opinions about these points and especially know more about the actual color of the Lucas additive and whether it may simply turn the oil white without meaning it is foaming (like add some Lucas to the gearoil without starting the gears: if it's white, the additive colors the oil but no foam can form without movement...).
Overall the article is great but I think it lacks real proofs. Unless the above points are clarified, it makes me think the Lucas additive is working as expected and there is absolutely no evidence to me that Lucas make the oil foam!! If indeed the additive was causing that much foam in the oil, any gearbox using it would break in no time! I guess by the time Lucas would be out of business or at least that additive would have been retired.
I'm not mostly favourable to oil additives but I do use Moly in my gearbox and it seems to work for me. Would be glad to know your opinion on these points!
http://www.bobistheoilguy.com/images/lucas/lucas.htm
I found this article very informative but I have a few remarks/questions about it:
1) In the beginning one compares a 80W90 blend with a 80W140 full synthetic. Prior to any additivation, one can see that the full synthetic climbs the gear much less than the blend. Even if the temperature is the same for both oil, the viscosity of the SAE140 is much greater than the one of a SAE90 grade so this comparison is not fair. That's not the point of the article of course but IMHO it would have been better to compare similar grades. The very best would have been to compare the same oil: once with additive and once without the additive...
2) The third pic shows that the full synthetic Pennzoil is getting white even prior to adding the Lucas additive!! So the Pennzoil is foaming a lot by itself and without any additional additive. Foaming is hence not caused by the Lucas additive but there is another thing going on here.
3) Adding Lucas makes the oil climb the gears but also turns the oil white. This means even more trapped air......or that the additive itself is white! Being in Europe I have no idea about the color of the additive. Can anyone tell if the additive is clear or dark by itself? If yes that may explain the light color. I mean I'm using MoS2 additive in my gearoil and without surprise the oil turns black! However this doesn't mean the oil is contaminated or that there is sludge dissolving in the box...
4) If foaming is indeed causing this white color, shouldn't we see a color difference between oil in movement and oil settling down in the pan? Obviously foaming occurs when gears are moving and oil is sprayed everywhere. After settling down for a while, some of the foam would dissappear and the oil should gradually turn back to its original color. A good test would have been to take a pic after 10min settling in the pan. If the oil was still white at the time, it would mean that Lucas additive, if not white itself, is turning the oil white but this would have nothing to do with foaming. Again think about Moly turning any oil black...
5) After all the Schaeffers 267 contains moly right? Is that really a fair choice for color comparison with other oils? After all, does a moly oil turns white when it foams?? I guess no....but it doesn't mean it is not foaming. Taking moly oils as a reference is IMHO the biggest mistake in this article.
I'd be glad to have your expert opinions about these points and especially know more about the actual color of the Lucas additive and whether it may simply turn the oil white without meaning it is foaming (like add some Lucas to the gearoil without starting the gears: if it's white, the additive colors the oil but no foam can form without movement...).
Overall the article is great but I think it lacks real proofs. Unless the above points are clarified, it makes me think the Lucas additive is working as expected and there is absolutely no evidence to me that Lucas make the oil foam!! If indeed the additive was causing that much foam in the oil, any gearbox using it would break in no time! I guess by the time Lucas would be out of business or at least that additive would have been retired.
I'm not mostly favourable to oil additives but I do use Moly in my gearbox and it seems to work for me. Would be glad to know your opinion on these points!
Last edited: