“Synthetic or Non Synthetic “That is the Question”
September 3, 2026

September 3, 2026

Michael Sachs (“The Jag Doctor”) is the owner of Sachs Automotive, Inc. and has been working on Jaguar cars since 1989. He is a former member of the Jaguar Master Technician Guild as well as an ASE Master Auto Technician and the official late model technical expert for the JCCNF. 

Two oil bottles pouring, with text: “Synthetic oil vs. regular oil: Which one is better?”

Let me start out by saying that I could write a book with lots of boring technical stuff that would not mean a hill of beans to the average car owner as well as most technicians.
So I won’t!


HERE IS THE SIMPLE TRUTH ABOUT SYNTHETIC OILS


First of all, SYNTHETIC OIL IS A PRODUCT OF CRUDE OIL. Hugh! What?
Yep, that’s right!


Diagram of crude oil refining to synthetic oil, with distillation column and chemical plant.

By refining the crude oil to the molecular level, the oil becomes a more consistent and pure product with evenly sized molecules, hence synthesized. Synthetic oil is also lighter in color due to this process. It is simply a better product with a higher cost.

Diagram comparing synthetic vs. conventional oil flow through engine parts, with orange and blue particles.

So is it the best oil for all engines. NO!!! The quick lube shops are the ones that started telling customers it was better for all engines and that they could go more miles between oil changes in order to justify the high cost and improve their profit margin. Also the Federal Government has had a hand in extending oil change intervals to lessen the environmental impact, regardless of the damage to engines and costs to the consumer. Hence, lower usage of oil regardless of consumer consequences.
 

SO WHAT OIL DO I USE, AND WHEN SHOULD I CHANGE IT?
 

So why do we change oil? For most people it’s because their dad or someone else close to them said you should do it to take care of your car’s engine. BUT WHY? BECAUSE IT’S DIRTY!


You should change your oil every 3-5 thousand miles regardless of whether it’s Synthetic or Conventional. The type (Not Brand) of oil you use should be determined by the manufacturer of your specific engine. It doesn’t matter whether you circulate conventional, synthetic, or liquid gold (well not gold) through your engine it gets the same amount of contaminates in the same amount of time and needs to be changed. Several things contribute to making oil dirty, combustion by-products, friction between parts, and even small amounts of unburned fuel bypassing the piston rings. Used oil is very acidic and can cause premature oil seal failure. We have seen a large increase in various seal failures since manufactures increased the oil service intervals upwards of 10,000 miles. 


When we change oil we are removing the dirt and debris as well as the acidic oil. Under even harsher than normal conditions conventional oil does not break down.


Recently, we had a customer come in the shop with an oil leak that appeared after he changed his own oil. The filter was leaking so we changed the filter. While doing so we found the oil to be very dirty. I asked him how long since he changed his oil and he said 2 weeks. Not good. You see when an engine is new, the system (engine, oil cooler and associated hoses) hold 2-3 more quarts of oil than you get out under normal draining procedures during an oil change. About 30% of the dirty oil remains. If you continue to extend your oil change intervals the dirt continues to build up at an alarming rate. “Hello sludge monkey” That’s why we need to change our oil every 3-5 thousand miles. The difference is whether you do mostly stop and go in town driving or highway driving. The more highway driving you do the longer it takes for the oil to get contaminated. But never exceed 5000 miles between oil changes, regardless of oil type. The exception is the cars that are driven less than 3000 miles a year only need to have the oil changed once a year.



One of the most important things overlooked today is checking your oil level on a regular basis. We don’t check our oil level like we used to, and the oil level is one of the most important aspects of an engine. It is not unusual for an engine to use a quart of oil during 1,000 miles of driving. Don’t fret, with manufactures requiring thinner and thinner engine oils in order to get better fuel mileage, this is quite normal. So you need to check your oil level every week or so. Cars used to have their oil checked every gas fill up. I am sure most of you remember the FULL SERVICE GAS STATIONS. For those of you that don’t, here’s how it worked. You pulled your car up to the gas pump, one or sometimes even two attendants came out (usually one was the mechanic) and asked, filler up? You then told the attendant whether you wanted regular or high test. “Ah, the romance of it all”
Remember the oil stands between the pumps? Pick your flavor.


Valvoline display rack with assorted motor oil cans against a gray brick wall

While the gas was being pumped into you tank the attendant would go to the front of your vehicle, open the hood, and check your fluid levels, with the oil being the first thing checked. If anything was low they would top it up.



So check your oil level often and change your oil every 3,000 to 5,000 miles to keep your cat purring like a kitten!

Close-up of a tire sidewall showing size, load, speed rating, and treadwear labels with colored callouts
September 3, 2026
Michael Sachs (“The Jag Doctor”) is the owner of Sachs Automotive, Inc. and has been working on Jaguar cars since 1989. He is a former member of the Jaguar Master Technician Guild as well as an ASE Master Auto Technician and the official late model technical expert for the JCCNF.
U.S. map showing states using red salt and gray non-salt de-icing products for snow removal
September 3, 2026
Michael Sachs (“The Jag Doctor”) is the owner of Sachs Automotive, Inc. and has been working on Jaguar cars since 1989. He is a former member of the Jaguar Master Technician Guild as well as an ASE Master Auto Technician and the official late model technical expert for the JCCNF.
Annotated engine diagram showing oil leak points and gasket seals with an oil puddle below
September 3, 2026
Michael Sachs (“The Jag Doctor”) is the owner of Sachs Automotive, Inc. and has been working on Jaguar cars since 1989. He is a former member of the Jaguar Master Technician Guild as well as an ASE Master Auto Technician and the official late model technical expert for the JCCNF.
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