If you've never used synthetic engine oil, maybe you should think about going with this high endurance lubricant. And if you do, when should you start?
There's always debate over the use of synthetic engine oil in classic Mustangs. Should you run synthetic engine oil in your classic Mustang and what do you need to know before popping the top?
Early on, synthetics got a bad rap because they tended to leak, especially with older high mileage engines. That was because synthetics didn't always get along well with old seals and gaskets. Over time, manufacturers have improved synthetic engine oil to where the benefits far outweigh the negatives.
There are three basic types of engine oil - mineral, paraffin, and synthetic. Most of what you see on store shelves are mineral (petroleum) based oils. Up side to petroleum based engine oil is its ability to soak up the impurities thrust upon oil such as combustion deposits. Paraffin based oils are more for heavy duty applications like we find in fleets.
Synthetic engine oil began use in gas turbine engines and automobile racing mostly. For example, jet engines have always used synthetic oil due to very high operating temperatures and extreme pressures. The thing to remember about synthetic engine oil is - it is still petroleum based, with a modification to its molecular structure. It remains effective at high operating temperatures where conventional engine oil tends to break down. Synthetic engine oil offers greatly improved lubricity at all temperatures.
Although manufacturers suggest oil changes every 7500 miles or so with synthetics, I change my oil every 5,000 miles with a filter change. Synthetics are darned expensive, but well worth the price in terms of what you gain in engine life. Need some examples? I have a 1998 F150 with 4.6L V8 with 200,000 miles showing with no major repairs. It sits alongside a 2003 Explorer with 4.6L V8 with 125,000 miles showing and no major repairs. Both are Los Angeles freeway driven. And both do a lot of cross country driving. Prior to these two Fords, there were other Fords that went an equivalent number of miles with no major repairs. Mobil 1 has proven itself a wise investment for nearly 20 years of steady use. I use Motorcraft, Fram Tough Guard, Mobil 1, or Wix oil filters in each of my vehicles.
With classic Mustangs, we suggest staying away from synthetics if your engine is older with a lot of miles despite great strides in synthetic technology. Stick with the oil you've been running all along. However, with a fresh engine, use conventional SAE 30 weight oil for the break-in for 500-1000 miles. Then, switch to synthetic 10W30 or 10W40 along with a high quality oil filter such as Motorcraft, Fram Tough Guard, Mobil 1, or Wix.
And finally, stick with one brand of synthetic engine oil in the interest of seal and gasket compatibility. There are several brands out there in addition to Mobil 1. Visit your nearest auto parts store or Walmart and check out the selection.
For more information on lubricants for Mustangs, check out our website at www.mustangmonthly.com.