The need or value of using synthetic engine oils has been a controversy for nearly as long as they have been available. Originally they were wanted solely for their duration and ability to extend the need for an oil change by double or more. Rumor has it, that when Mobile 1 came on the market, General Motors was approached and pitched on offering their customers’ vehicles that would only need an oil change once every year. It was supposedly shot down by their dealers’ need to get the customers back in for regular service, a needed steady money maker.
Well, it appears synthetic is no longer thought of as an extender of oil maintenance as nearly every engine manufacturer warns against extending the duration of oil changes regardless. Still there are people that believe it is possible and will work well. I’m not one of those as I prefer to follow the manufacturer’s recommendations. It may also be questionable as to the quality and type of filtering that we use today equaling the performance that these oils can apparently deliver.
So let’s see the balance, what other benefits can be found in using the higher priced oil? One of the prime benefits is the ability to operate more efficiently than regular oil brands in extreme temperatures, both high and low. Generally this would be needed more in high performance gasoline engines or in engines exposed to extreme winter temperatures. So are there any real gains to using synthetic or even partial synthetic in a motor home or RV towing vechicle application? For heavy gas powered coaches or heavy pick-up trucks, probably. While the engines are not what one might think of as high performance engines, they are subjected to extreme heat when accelerating the heavy vehicle and while climbing steep grades. Diesel engines however, are a different story. It is probably not as beneficial when used in the slower rotating engine that generally runs cooler.
So, is it of any benefit to using synthetic oils in modern diesel pushers? For the engine itself, perhaps little. But, for the high RPM turbo chargers and for the built-in compressor units, it may be quite beneficial. Turbo charger turbines turn at 90,000 to 220,000 RPM depending on the make, model and application. The speeds and heat are so high that many bearings would not survive, thus the shafts are generally rotating in the bearing suspended on a thin film of oil. Both cold starts and hot shutdowns can have their toll on the turbines and bearings. Synthetic lube allows much colder starts and far hotter shutdowns, with no coking in the bearings that can happen when using conventional lube oil. Likewise the superior lubrication qualities found in the synthetic at the extremes at either end of the thermometer protect the moving parts within the compressor and related components.
Let’s look at some of the good points and some of the bad.
Synthetic Oil Benefits
- Runs cooler with reduced friction
- Superior cold and hot engine performance
- Resists the forming of sludge
- May help to reduce fuel consumption
Synthetic Oil Drawbacks
- High cost of purchasing
- Not available at every service station
- May not be advisable for use during break-in period
So, is it worth the extra money? In my opinion, probably not. That isn’t saying it is not a good or better lubrication, on the contrary it is a great product. No matter which brand it is. But, it is when the costs enter into the equation that it starts getting hazy. I mean, granted it will not coke in an overheated turbo charger, where it would with standard oil, but, if the engine and turbo were properly cooled down prior to shutdown, they would be virtually similar.
Having said this, I do use synthetic oil in my Cummins ISM and did in my previous ISC. I also use synthetic in my Escalade toad, our house stand-by generator, and previous personal vehicles. A motor home, in my opinion, whether gasoline or diesel, is subjected to infrequent use or long down periods and therefore may well support the added cost for synthetic oil use.
So, what’s your take? Do you use synthetic oil or conventional?
Looking At The Age Oil Question – Lug_Nut – Peter Mercer