Your would need to check the ratings of the 5 gallon buckets. I don't know which is the newest so maybe you can find someone with a early bottle to compare to. I do know in '07 the diesels changed to low sulfur fuel and converters were added, so it only figures the oil changed at the same time.
The Rottella will still have zinc in it and probably enough for a stock engine, but the 15W40 is just to thick in my opinion. These small engines just don't work hard enough for this grade of oil.
Sure wish someone could find a good comparison chart thats up to date on oils and additives.
Joe
