Is Synthetic Motor Oil Bad For Old Cars?

Can you use synthetic oil in old cars? Can synthetic oil cause leaks?

We’re tackling many heavily debated subjects about motor oil in this video and learning how specially formulated motor oil can help new and old engines add more miles to the odometer! Can you use synthetic motor oil in old cars? Can synthetic oils cause leaks in old cars and engines? Where did the idea originate that synthetic oils are not compatible with old engines? If your car is consuming a lot of oil, should you use a thicker oil grade? Finally, when should you use a high mileage oil? I spent time discussing these questions and more with Mobil 1 engineers. Watch for all the details! #Mobil1Partner

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[davidellis]

I used to be in charge of a large haulage fleet running heavy trucks, we used to use sae30 in summer and sae20 in winter, one of the engines failed and seized up the crankshaft, we put that down to oil pump failure. A Chemist came in from Shell at the Bosses request and we discussed this multigrade thing at length with regards to thick and thinner oils which made me think about things in a different way. I was always in favour of thicker oils to maintain oil pressure at running temperatures, he explained to me that thinner oils flow easier at low temperatures so lubricate better when the engine needs it most at cold starts, he also said that engine oil was not just for lubrication it’s was there to cool the moving parts by keeping the friction between them to a minimum. A thin oil will pump round the engine quicker than a thick oil so the more oil circulating the more cooling is taking place even if the oil pressure isn’t quite as high, he convinced me and the boss and we changed to 10w30 in winter and 15w40 in summer, some of our engines went on to do over 1-5 million miles without any problems so I think he proved his point.

[Vexman]

This video is going to get a lot of views once people start linking it in forums for the weekly "what oil do I need" question

[robs]

Hasn't anyone noticed that most oil companies have quietly switched to synthetic blends?? It seems harder to find straight up conventional oil anymore.

[davethewave]

I had a customer who was a mechanical engineer, although not in the automotive industry. He was very meticulous and studied everything. He bought a used '85 Lincoln Town Car with a F.I. 5.0 liter. It used a lot of oil but had no visible leaks. He was sold on synthetic oil and it's improved detergents. He changed to Mobil 1 and then after 500 miles changed again and then after 500 more miles changed again. After each change his oil consumption dropped and continued to drop. After the 3rd change he ran the oil for 5000 miles and changed it at that point there after. It had very minimal oil consumption after that, approximately 1 quart between oil changes. The car had about 70k miles on it when he originally purchased it and it had about 130k when I met him and took over as his mechanic. I know the car had been owned by an elderly couple before he purchased it so I assume many years of low engine speeds and probably poor maintenance had resulted in carboned up rings but the fact that using regular Mobil 1 cleaned the engine up so fast was pretty impressive.

[beefchillingham]

So these are the essential oils I’ve been hearing about

[apegues]

This video has been needed for a long time, I’ve been fighting this myth for 40 years of my 45 years as a mechanic and shop owner

[leroyusa]

As long as your engine isn't burning alot of oil due to poor maintenance. Increasing the viscosity can help. The bottom line is to decide if the synthetic oil is actually worth the extra cost. More frequent oil changes can never be a waste of money or time if the engine is only driven for short runs or non freeway use. Freeway driven miles, in my opinion is better for the engine. The engine has a better chance to burn off the accumulated contamination like carbon and sulfur.

[kendall]

I had two motorcycles which were two cycles. I used synthetics to eliminate exhaust smoke. The synthetics also eliminated the carbon deposits on the piston crown.

[ornessarhithfaeron]

I only put the purest olive oil in cars

[autohut]

I hated dealing with old farts at Autozone that would run 20w50 in their 2015 Corolla because “that’s what I ran in my 87 Chevy truck”

[kenvitale]

Jason your videos are always top notch. I like them because I learn stuff, and you never over burden our ears with annoying music that so many others feel is needed---instead you give s more information than us "regular guys" can mentally absorb in one viewing. So I generally watch them more than once.

[robertwright]

Just for informational reasons. If your oil light flickers and the oil level is okay check the oil psi sensor before switching to a higher viscosity oil. I have found this issue on several vehicals.

[atarvhegde]

Finally a Engineering Explained video which I may understand

[d.e.b.b]

I've been using synthetics in old cars ever since Mobil One was first available to me in 1976. Never had a problem. Haven't had any mechanical engine failures, either. It was a great advancement in motor oils, and proved that thin oils can lubricate just as well as thick ones.

[DawnBriarDev]

One thing you missed:
Regarding high mileage oils, they usually have higher concentrations of detergents and dispersants than "low mileage" oils, in addition to seal conditioners. This is intended to gradually clean the engine over time, rather than using a "flush" which can clear buildup quickly enough to clog filters, screens or orifices.

[michaelkolbe]

Valvoline full synthetic I've used since I bought my car and change it every 3000 miles and it's never dirty or broke down .Great stuff ! I use Valvoline full synthetic 5w30.Also use Toro full synthetic in my tractor, mower, power washer, snow blower .

[davidbrogan]

I've been using Mobile1 since I bought my '04 F250. Now has 342K and I often don't change oil for 10K - 15K miles. Of, course I pray for protection also.

[watersauce]

I've driven nearly a million miles between 5 different cars all older than 2002 (delivery driver) using only Mobil 1 synthetic for the last 16 years and I've never once had an oil related problem. I change it about every 8k miles.

[jimpinkowski]

Perhaps the most extreme example of burning oil might be my '53 Johnson Seahorse 2-stroke running on a gas oil mixture of 15-to-1! Using non-synthetic oil, I had to clean or change the spark plugs after about 10 hours of operation. Once I switched to synthetic oil (still using the 15:1 ratio), I never had to change the spark plugs again!!! This made such an impression on me that I started to use synthetic oil exclusively when I bought my '79 RX7, that burns crankcase oil by design to lubricate the rotor. In 23 years of driving, I got 320.000 miles on that engine and it was running fine and smoke-free when ! finally sold it for a larger car!

[sptrader]

Switching from conventional oil to synthetic caused leaks in a couple of old cars that I owned too. That is the main reason many people won't switch in older cars (70s-90s). In a newer car, I would only run Synthetic.