Engine oil coolers are more important that you would think. When most people think of an engine oil cooler they think of a big heavy duty truck (F350) towing and hauling.
Truth is modern cars don’t just push oil through their engines… they more or less chew it up and break it down. Again I’ll leave the specifics about which oil brand/type is the best for discussion on the BITOG forums. www.bobistheoilguy.com
So what does this have to do with oil coolers? Well Ford upped the 5.0L coyote motor to 8 quarts to help keep the engine cool instead of a large engine oil cooler up front. They also mention that an oil cooler is recommended if you plan on track use… who buys a Mustang and doesn’t put the pedal down to the floor… really??? Ford did use an air-to-water cooler (see below – not mine just found a quick pic on Google) but those are pretty much useless. Yes they do a good job of warming the oil up to temp with the radiator fluid, but at the track your radiator fluid is typically screaming hot. Not good for your oil.
Enter an external engine oil cooler. Warm-up may take a little longer, but you can always use an external bypass until the temps come up. A bypass works by short-circuiting the fluid path… basically the fluid short cuts around the cooler and goes back into the engine until it gets warm enough. Then a spring closes off the short cut and the fluid now is forced through the cooler. If you plan on any sort of track day an engine oil cooler is a must; its cheap insurance to help your engine oil keep your engine alive. Those of you that don’t drive on a track but have teenagers at home – your car has seen more ‘track days’ than you think. Even if you drive slow but live in a southern climate where the summers are a beating – go with a cooler. 110°F outside temp only compounds this problem further.
Many people see an engine oil cooler and think they can short cut with a transmission cooler. WRONG! Transmission coolers are designed for lower flow rates and should NEVER be used for engine oil cooling unless the manufacturer says its OK. Most transmissions run in the 1 to 2 GPM range and use 3/8″ lines and fittings. Engine oil coolers should have 1/2″ lines and fittings and a cooler to match the flow as well. An engine oil cooler should support up to 4 or 5 GPM – much less will begin to restrict the oil flow.