THE TRUTH ABOUT AUTOMOTIVE FLUIDS
All of us who have maintained a vehicle have been to a lube shop and had a card or pallet presented to us with a sample of our vehicle's fluids on it and likely a suggestion on which fluids to replace. We feel slightly intimidated, and depending on our finances, time, and how "honest" we feel the salesman presenting the suggestions make our determination on whether or not to do the recommended services. The truth is mileage and driving conditions are the only factors that should come into play when maintaining our vehicle.
The best way to know how to maintain your vehicle is to keep a maintenance log and review it prior to each oil change. Better yet, take the log with you to your mechanic and go over it with him prior to buying anything. If you bought the vehicle used and don't know the maintenance history, go to a reputable shop, and get an idea from them as to what has been maintained properly and what has not. Then formulate a plan to get all fluids replaced and start the log from there.
Fluids are the life's blood of the vehicle. They are designed to protect the components of the vehicle. Fluids lubricate, dissipate heat, protect from corrosion, and provide a near incompressible medium for hydraulics. The best way to get maximum mileage out of your vehicle is to keep the fluids like new. It will always be cheaper, in the end, to maintain your vehicle than to repair it. Oil leaks, coolant leaks, check engine lights, brake issues, driveline noises, and almost all repair work can be eliminated by proper preventative maintenance.
All fluids have "additives" that are designed to clean, neutralize acidity, protect seals and gaskets, prevent foaming, and prevent sludging or build-up. The problem is that these additives are very expensive. That is why different brands of fluids have such drastic cost differences. Typically, the more expensive the fluid, the more additives and thus, the longer it "lasts" or protects the components it is designed to protect.
Since we are becoming more informed about fluids, let us discuss the "Manufacturer's Service Intervals". The perception is that "As long as I follow my Manufacturer's Plan, my car will last forever." That is not true. Following the Manufacturer's Recommended Maintenance Schedule, will result in your car going strong to 100,000 miles and then breaking. There are two reasons for that: First, manufacturers want to sell cars, so they make them last for a finite period of time, and then you need a new car. Second, the "Cost of Ownership" classification. The major research companies rate vehicles on total cost of ownership over a 100,000 mile interval by calculating price of the vehicle, fuel economy, insurance, and recommended maintenance. With an average of 10,000 miles driven per year, that breaks the car up into 10 years and thus the calculations can be approximated. So, manufacturers moved the maintenance intervals to 105,000 miles for most fluids and even tune-up items. Will the vehicle make it that far? Yes, but damage has been done that will require major repair in the near future. The truth is the fluids have broken down and stopped protecting components long before the 100,000 mile mark. Manufacturers have even extended the oil change interval to put fewer oil changes into the calculation. Talk to the service advisor at the dealership and he will tell you that oil is so much better than it used to be. It is better, but fluid does work. Any work that must be done has a price. As a technician, changing oil in thousands of vehicles, I have noticed that oil doesn't typically turn dark in a new engine until about 5000 miles depending on the oil it could be 7500. That being said, by the time you see the change in fluid, it has already stopped protecting.
So that is The Truth About Fluids. You may still be asking “When do I change them and when do I tell the lube salesman to buzz off?
These are the intervals I personally recommend:Engine oil: 5,000 miles*Transmission Fluid: 30,000 miles*Coolant: 30,000 miles*Power Steering fluid: 30,000 miles*Driveline fluids: 30,000 milesBrake fluid: 30,000 milesInduction Service: 15,000 miles* with quality fluids plus an additive package.
Now these are my recommended maintenance intervals using additives. If you are not putting extra additives in the fluids, I expect these numbers to diminish drastically. When you buy a new vehicle, the fluids that come from the factory likely have these additive packages in them to make them last as long as possible, but fluids always break down.
Please note that other items like spark plugs, brake pads, shocks and struts, ball joints and bushings and many more are maintenance items, but do not come into contact with fluids, so I didn't mention them. These items wear differently and must be considered on a case by case basis. Double platinum or iridium spark plugs will likely last to 100,000 miles if the fuel system is maintained properly. Shocks and struts are likely due between 60,000 and 100,000 depending on the terrain. Brake pads, ball joints, and bushings all depend on driving habits and terrain and are inspected during routine services. The wheel alignment is another thing that needs to be checked every couple of years, if something doesn't feel right or if tires have been replaced.
My goal as a technician is to keep your vehicle running like new through 500,000+ miles. I believe that fluids maintenance is the key. I wanted to help inform vehicle owners of the importance of fluids and give them some information to have confidence when going into a shop. I hope this was helpful, and please feel free to research this more and comment.
David PittmanASE Master TechnicianNetwork Automotive Service Center