Choosing the best lubricants and oils for commercial trucks is a constant topic of debate amongst owner-operators. A better product translates into money saved by decreasing wear and maintenance costs, and increasing fuel mileage. The old conversation about choosing synthetic lubricants or non-synthetic oil was recently revived on the forum:
In my VN670 with 16 liter volvo engine I use Delvac fully synthetic oil since new. Change interval 50000 miles (according to manual using mineral oil change interval 25000 miles). Hope to see your comments soon guys.
My buddy also uses Delvac 1 in his truck, I think he said he changes oil around 60-75k, but changes the filters at 15-20k.
All the research I’ve read seems to suggest that you can use regular oil during the mild weather months (spring and fall) and use syn during the rest of the year, since syn oil’s increased resistance to temperature extremes helps the most then. But of course, using it all year round won’t hurt anything, and should help keep your engine cleaner (on the inside).
Some drivers discuss fuel mileage improvements:
I use Amsoil’s Heavy Duty Diesel full synthetic, and also use Amsoil throughout my truck for the transmission and axles. This is on a 2000 Volvo with Cummins N14.
When I first bought the truck, it came with what I’m sure was conventional oil. After switching, I immediately noticed that my truck was running cooler on hills. Where the fan would kick on at the top of the hill before, the temp wasn’t even getting close to that.
Fuel economy also started to climb. I was getting an average of about 6.1-6.3, and now I post 7-7.5 pretty steady.
I have always used synthetics in my vehicles. After seeing a dyno test done by a Mustang publication years ago, it really changed my mind. The test Mustang actually got 5 extra hp at the rear wheels! Add to that the extended drain intervals, and it’s a no brainer.
Add another vote for synthetic AMSoil:
I definitely agree with the intervals and also the mileage, I was barely hitting 5.5 with the oil in my truck when I bought it (bought an ’01 Columbia Daycab earlier this year). AFter having the engine flushed and putting in Amsoil 15w40, I”m now getting well above 6.5, on the exact same run in the same temperatures.
ANother thing is the TBN number which the higher the better, and makes it last longer too.
For the price diff between amsoil and other oils, I just use the amsoil on everything, from my cars to truck to lawnmower.
The preference for synthetic oils in this conversation is clear, but some drivers dispute the value of paying more for pure name brands, and would rather save money with synthetic blends:
I ran the Amsoil for a while, then I was on Schaeffer’s. Compared to dino oils, I got a little more life out of the synthetics, but wear numbers weren’t any better. I eventually started using a synthetic blend from a regional oil distributor and have had the best results. Most of the off the shelf blends are 25% or less synthetic in the blend. My supplier has their stuff done up with a 40% blend. I get it for around $9 a gallon total cost delivered to my home in a 55 gallon drum. The name brand synthetics are just not that cost effective for me. I have found that engines are like firearms. Some firearms just plain perform better on certain brand names of ammunition. Likewise, some engines do better on a particular brand of oil. Mine didn’t do any better on the high end boutique synthetic oils.
In researching out what I ended up using, I found a lot of good information. Motiva is the largest supplier of base oil stocks in the world. They make the majority of base oil stocks for all the engine oils you see on a retail shelf. Infineum makes a large portion of the additive packages for the engine oils. My distributor uses these same suppliers and puts together their own particular oil concoction and charges far less than the labled plastic bottle brands.
Now when everyone else can get their synthetics down to $10 a gallon or less, I will reconsider. But since the performance has not been better for me than the current oil I use, I will probably just stick with what is working for me.
The full thread with additional information is available in the trucker forum.