Synthetic Oil or Not for Low Use Vehicles

[PaulZ]

I have been doing yearly oil changes on two fire trucks, a 2016 and a 2019, both F450s. They are lucky to see 500 miles in a year. They do idle a lot at calls. I've been using conventional oil and haven't kept up on modern oils like synthetics. Would there be any benefit in this situation?

 

[Blmpkn]

 

[fastpakr]

I wouldn't bother in that use case. Oil can become acidic after it's used and allowed to sit, so you should end up changing it at least yearly regardless of what you're using. I don't see synthetic providing any useful benefits here.

 

[Uncle Gump]

I would ensure that the conventional oil you're using meets the specification for the engine.

I would even go a step further and just use the recommended oil from your owner manual.

 

[Roert42]

I agree with gump. See what the manufacturer recommends.


Although In your case low miles doesn’t mean low use. A lot of hours at idle will cause just as much wear as highway miles.

 

[sgtsandman]

I agree with just sticking with dino oil for that. Change the oil according to what the manual says. Until fairly recently, it was a certain mileage or every 6 months, which ever comes first. I tend to prefer that over the once a year they are recommending now.

 

[Blmpkn]

I agree with gump. See what the manufacturer recommends.


Although In your case low miles doesn’t mean low use. A lot of hours at idle will cause just as much wear as highway miles.

IIRC "they" say you can consider an hour of idling to equal roughly 30 miles of driving.

 

[09fx4guy]

Paul- I would rather see you change it every 6 months with a quality oil, what is recommended by the manufacturer is just fine. Sgtsandman is right.

Considering you are working on lifesaving equipment, I would rather err on the side of caution than risk mechanical failure during a crisis / emergency.

 

[Bill]

Synthetic is better if it is idling, but given the low mileage put on the oil it probably doesn't matter. Also, synthetic is about the same price as conventional oil, and out here I only see a few brands of conventional oil. Supertech and Castrol. Sometimes Valvoline. Everything else is a synthetic blend or full synthetic.

 

[PaulZ]

Thanks for the replies guys, I know it's a debatable subject..

 

[cschannuth]

As long as those fire trucks are always brought up to full temperature whenever they get started, anything you use and change annually will be more than fine. Trouble can start with any vehicle if you start it up and turn it off immediately to move it out of the garage or the fire house as an example. It doesn’t allow the moisture to burn off in the crank case and that can cause issues.

 

[PaulZ]

So the decision was made for me.. I was grocery shopping at Costco and checked out the automotive isle as I usually do. Mobil 1 was $10 off a case ($30 for 6 quarts, regularly $40), cheaper than even Kirkland oil, so I bit. Did both rigs last night. Thanks again!