Oils ratting and the TBN question

Not open for further replies.
Feb 9, 2004
Hi all, Ok a bit hard to explain, but, what I'm a bit confused about is I have noticed that there are several oils that are SJ or SL rated and have a TBN of 6 or 6.5, then there are there cheaper cousins that are 7.9. Now wouldn't the Higher rating like SL qualify for a higher TBN???? (Australian, Mineral oils) Eg: Valvoline XLD Plus 20w 50 SL/CF. TBN 6 Valvoline XLD Multigrade 20w 50 SG/CD TBN 7.9 I have noticed this is a few other brands also.
quick answer: Starting TBN has esentially zero to do with API rating. An oil could be spiked with NaOH and the starting TBN will be sky high, but to oil may be crap...... long answer: learn a lot more about motor oils and you may start to scratch the surface....
Adding to what Pablo said. A high TBN is usually a good indicator that the oil has a pretty good additive package. On the other hand, the other oil with an SL rating has had to endure tougher volatility testing than the SG rated oil and as such probably has a tougher base stock. It could be however, that the XLD product simply has not been submitted for SL testing. It very well may be capable of acheiving and SL rating. At the end of the day, if you are going to run the oil for a 3000 mile drain interval the differences between the two may be negligible. If it were my money, I'd buy the SL rated oil. In that case at least you know it is formulated to meet that spec. Don
Originally posted by Francis: Now wouldn't the Higher rating like SL qualify for a higher TBN????
Not unless they would make it part of the SL specs... Sj or SL would be like 4 jumping jacks vs 5 jumping jacks with each respective ### of sets (equal to one rep) and then to repeat "X" sets of jumps "X" equal to the afore mentioned to 10 sets would be 10*4=40 vs 10*5=50 ie different parameters PARAPHRASE There are sets of rules to follow, and each set of rules to follow unless it says in specific to the content of the duration or quality or quantity of the TBN or TAN or any other factor, will be left up to the characteristics of the oil formula originally decided to be the solution to the marketing plans of the company that developed the oil.
Not open for further replies.