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.

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

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

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.

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

I only put the purest olive oil in cars

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.

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.

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

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”

This guy is a tremendous communicator of knowledge.

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 .

Finally a Engineering Explained video which I may understand

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.

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.

They told me the same thing, use thicker oil and I did switched from the factory recommended 10/40 to 20/50. The engine started to rattle and vibrates (very similar to a bad engine mount), harsh cold start and slightly worse fuel economy. Switched back to the regular 10/40 and the engine back in shape immediately. Its debatable but from my personal experience ALWAYS stick to factory recommended viscosity.

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.

My dad ran the section at Mobil that developed Mobil 1 if you are interested in doing another video on the topic that goes even further in depth.

I think another issue is the longer oil change interval. Whether conventional or synthetic more frequent oil changes help.

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.

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.

I was expecting him to drink oil out of that beaker, and judging by how he looked at it, he was probably thinking the same.

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.

been using mobil1 in every car an mower back i 75 ...thanks to it ..my vw bug started when we had the big snow in 78...

The leaks were there already, synthetic just allowed the hidden to be apparent.

I use AmsOil in my 79 Continental, 86 Grand Marquis and 86 F-250. All are getting old, and all of them run GREAT on high end synthetic. If anything, it has greatly reduced oil burning and leaking.

For me with my 1967 Wolseley Hornet I use a conventional, 20w50 blended specifically for classic engines. The A-series engine has larger tolerences so the thicker oil is recommended.

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!

Absolutely brilliant video, Jason. You are a world-class communicator.

Thank you for explaining the history behind some of the reasons they initially got a bad rap. And why you would use different viscosities vs different additives, high mileage etc... great vid!

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.

Nicely done. My 2001 VW Passat wagon, with its longitudinally mounted 1.8T engine and undersized oil sump, has thrived on Mobil1 0W-40 "[Spoiled] European Car Formula" and the largest oil filter I can cram between the oil cooler and the left engine mount, a Mann 950/4. When we replaced the valve cover gasket last year, the top of this "sludge monster" engine was clean.

Switched my old impala over to synthetic and have had zero issues

I use Royal Purple synthetic in my 87 wrangler and haven't had any problems

Mobil 1 Full Synthetic Oil is my favorite oil. I've used it on my Ford F-150 with a 3.7 L V-6 engine for 11 years and at around 149K miles the engine runs as well as when it was new. Thank you, Mobil 1 and Engineering Explained! 👍👍👍👍👍

As a 3rd generation mechanic I always chose Valvoline in my fleet and use OEM agency filters ie Motorcraft Or AC and so on.. always use the appropriate API grade

i had a significant mct-oil consumption last month. leaking only occurred when taking too much

Debunking car myths one oil at a time. Good work as always my man. ❤️

Thanks for posting this. It contained quite a bit of useful information. Back in the OLD days, rear main seals were made of rope, and as time went on, those seals turned into almost like wood, and the sealing swelling issues failed, causing those seals to leak.

Good video! Another reason to not use synthetic in an old car that already burns oil, is the cost associated with burning the expensive oil! I think I would buy the cheapest oil until I could replace the car. Amsoil advises to install their oil in mechanically sound engines. A car that has been running on conventional oil for 150,000 miles probably isn’t all that sound any more due to wear and sludge build up, even if changed often,because of higher volatility and lower maximum operating temperatures compared to synthetic oil.

I love how the top of those jugs line up with the lines in the wall.

High mileage oil has seal conditioners that recondition your old dried out seals. They also have different cleaners to remove old sludge.The engineers spent years developing these oils so use them.

Rotary Head here I am glad you touch base on the rotary engine in the end. I have been using synthetic oil since my '91 RX-7 Turbo II back in 91. Also in 93 RX-7 R1 and 07 RX-8. The only time I was told not to use synthetic oil was having mineral oil in the rotary engine long time and switching over. But I have always removed the original mineral oil from new and switched over to synthetic. I have also talked to a lot of rotary engine builders and all say the same. Again thank you for touching on the rotary engine and the myth about synthetic oil

I have been running Synthetic oils in my Hi Mile Cars for the past 15 yrs. Some were switched with over 200,000 on them, no problems

You haven't addressed the need for ZDDP in "old" engines, those with flat tappet cams. Much more important than leaking seals.

My brother recently bought a Daihatsu HiJet (one of those cool little mini trucks with the steering wheel on the right). Interestingly, the service manual contains a clear warning NOT to use higher viscosity oil than recommended as it will create a risk of damaging seals and gaskets due to over-pressurization, thus causing leaks.

Great video and education. Thanks for sharing!!!! I learned so much.

Had an old car with no leaks. Added synthetic. Leaks started from every gasket.

I have an older, high mileage engine. Used 5w30 had 15 psi oil pressure at idle. Switched to a 5w40 now I had 20psi at hot idle.

Decades ago my dealer asked me not to use synthetic in my Mazda RX-7 Rotary Engine. Mazda also had a sticker with the same statement under the hood. I was told that the rotary engine did not get hot enough for synthetic oil use in the 1990s. I moved a few times and multiple Mazda dealer service shops enforced high quality conventional oil for rotary engines as they ran cooler.

Thanks for the video! It made my decision easier. I have an old '99 suzuki car with moderate/high milage(at least about 170 000km) and I switched from part synthetic/hc synthase (10w-40) to a synthetic oil (5w-40). No problemes so far, car starts a bit easier. I didn't have any bad experience, just positive. I mainly switched due to extreme weather conditions in Europe (cold winter days, really hot summer days) and it should be cleaning and protecting the engine more effectively. at this age, it might be even more important. I rather go with a cheaper, but quality brand, but put synthetic from now on. Next time I'm thinking of trying a full synthetic of this grade.

From my own experience, when i changed from a mineral oil to a semi synthetic oil on an old hilux, i needed to change the filter after a couple of 1000 kilometers, it was full! Then I changed the oil and filter again after like 5000 kilometers, after that back to normal intervals.

The question is, what is considered "old" car?

Your videos are thee most informative & thorough on the net. Thank you, sir 👍

good job of explaining old questions that I have argued both sides of! Thanks

I was confidently rebuilding engines at 19 years old, and applaud your video - online with my experience - that synthetic is the way to go. The last bastion of fighting a thicker oil is variable valve timing mechanisms being knocked out of sync. And of course syn's are thinner than comparable standard oils.

I put 0w20 in my Tesla model 3. Still clear as new after 20k miles. Do I still need 0w30?

Very useful info. Bite -sized presentation. Perfect!

Very informative. Excellent job explaining

WHERE IS THE BOARD?

Thank you for the bonus on the rotary lol I was hoping to hear about them and I'm glad you mentioned them

8/2023: Very Educational. Questions answered, and, new information. Thank You and Best Regards.

One thing that's very important when using any modern oil in an old engine is zinc additives for very old cars with flat tappet camshafts

One additional thing you should’ve touched on is the lack of zddp in modern synthetic oils that were used to protect flat tappet cams in old engines.

The majority of UK RX8 engine rebuilds come in the first 80k miles, so perhaps we never needed to worry about what oil we were putting in... You can clean the housing faces and rotors while it's in bits after all!

Thank you very much for explaining in detail.

2003 Chevy Avalanche 416k + miles Mobil 1 is great. Changed the plugs bout 10 k ago compression check showed 8 cylinders within 5 psi. Called Mobil1 at 400 k miles they congratulated me and told me to call back at 500 k, must be quite a few in the 400 k range.

Moving out on your own and realizing(but already knowing) that your truck-driving dad was a genious.

As usual, your explanations make total sense. Your flickering oil pressure light hit a nerve with me. My 96 Impala SS (purchased new) had about 275,000 miles on its 5.7 liter LT1 when I started noticing the dreaded flickering oil pressure light. No oil pressure gage came with the 96 Impala. The engine has never seen any oil except Mobil One 10W-30 - changed every 5,000 miles without fail. The light would only flicker on a hot summer day while idling at a red light with the AC blasting on high. I tried switching to Mobil One 10W-40. I could not see any significant improvement. I finally had to admit that the old LT1 is worn out. It has since been replaced with a rebuilt LT1. No more flickering oil pressure light. 8-)

I like the synthetic blend High Mileage oils. My wife’s 2010 Chrysler town and country with a 3.8 liter V6 had a TSB on these engines were prone to consume a quart of oil between 700 to 1,100 miles from the factory. Our van already had 101,000 miles when we bought it. First time I used what the engine called for which was 5w20 and by the time it was due for change it used 2quarts of oil. I’ve tried many brands of 10w30 but no success. Finally I was suggested to use a High Mileage synthetic blend oil which was Castrol High Mileage synthetic blend 10w30. By the third oil change it reduced consumption in half and I’ve been sold ever since.

All motor oils now have seal conditioner, both synthetic and non-synthetic and not just high mileage oils, which are slightly higher in viscosity. The one engine I remember higher viscosity oil fixing excessive oil consumption, is the old Ford Escort, that had crankcase ventilation issues. Just going from a 5W30 to a 10W30 oil, actually reduced oil consumption to an acceptable amount in those engines.

Loving this one brother thank's for sharing very important information giving blessed love to all knowledge is power hopefully everyone pays attention keep up the good work 🙏🙏🙏🇯🇲🇯🇲🇯🇲💪💪💪

Thank you for that. Cleared up a lot of questions I had.

Wow really great content. Great work guys respect

Many good points made here. Confirmed many of my own theories about motor oil.

Followed instructions as best i could but this deep fried chicken has a weird taste to it.

I've just passed 300,000km in my car running Mobil1 since day 1, maybe it's time to switch to high mileage stuff as my consumption has reached 1L/1500km, although I found one of the two PCV ports under the throttle plate clogged which once un plugged seems to have reduced the consumption a bit. Still, no leaks, no visible smoke and no loss of performance at this mileage made the premium oil investment well worthwhile long term.

My 2004 Jeep Grand Cherokee, equipped with a 4.0l , has run Mobil1 10w30 since new, she now has 453,000 miles and still runs great, all original engine.

This was a great video. Thankyou. 👍

So *that's* what the crosshatch pattern does. Huh. I learn something new every day. Thanks!

240k on my 99 civic used on my courier job. Supertech high mileage synthetic oil keeps it running great

Thank you for the great info and great video

Very informative!

This is a very good and informative video. Thank you Dexter Manley.

FWIW, I’ve been using synthetic, usually Mobil 1, for about 15 years in my ‘91 RX7, which sees a lot of track use. It’s still on the original, unopened factory engine, with good compression at 170K kms, although an internal coolant seal has failed, so I’m finally going to have to crack the keg.

Been using Castrol GTX for years and years. My old truck on the farm has 284,884 miles with no major work. Had to install a new $117 alternator last month though.

I switched to Mobil 1 full synthetic after my 97 Oldsmobile’s engine suffered a catastrophic failure at 122,000 miles. When the engine was replaced with a series III, I ran full syn ever since and my car runs and performs better now than it ever did ❤️

I became a synthetic oil user way back in 1982. I was introduced to Amsoil 2 cycle oil because I was having issues with a weed trimmer and chain saw. Switching to the Amsoil products instantly corrected my problem, so it was logical to try the 4 cycle oils that were available then. The results were dramatic and as Amsoil has moved onward and upward with their products, I have never stopped using them. I have kept detailed records of everything vehicle , and lawn equipment. For example: I owned a 1994 GMC truck with 4.3 liter. I had that truck for 14 years. I sold that truck in 2008 and it had over 210,000 miles on it. Everything had Amsoil synthetic lubricants. I can tell you that 2 years later the buyer called me stating that he continued using the same oils and the truck is still performing fantastically. I currently have a 2002 GMC Sierra with the 5.3 V8. currently has 145,950 miles on the odometer. Still has the same all around performance as when it was new. I also know that if you have a vehicle that always used conventional oils, and you are considering switching it to synthetic, there is a correct way to do that. I know this for a fact because I purchased a used vehicle for my son. I followed the Amsoil recommended procedure of implementation of switching to synthetic oil. That vehicle responded very well. My son drove that vehicle for several years. I have had many different situations with different engines types and makes and I can tell you that I am never going to ever use conventional lubricants. I can also say that Mobile 1 does NOT hold a candle to anything Amsoil has. And just in case you're wondering.... no I am not a dealer or distributer of Amsoil products. Just a 30+ year user and damn proud to say so.

Love your videos! So informative, entertaining and aesthetically pleasing lol

The single most informative video on car engines I've ever watched

This video…. Absolutely fantastic

Mobil 1 high-mileage synthetic has saved 3 of my old vehicles by stopping minor leaks that would be too expensive for me to fix otherwise. One has been leak free for over a decade since I started using high mileage synthetic oil.

Thank you for debunking old myths!

Thank you sir, great video!

thank you very much for such an useful information that not everyone knows.

I had a an engine with 375k miles and it had some weak compression rings and would smoke a lot if it idled long but wouldn’t smoke if you just went on your way. It did consume about a quart of oil a week. It used enough oil for the last 3 years that I owned it I never changed the oil, in fact I put the used motor oil from my other vehicles in it that I removed from my other vehicles.

Thx for the rotary excursion in the end. :)

I've been using 0w40 mobile1 in my e38 for a decade and a half and it runs better now than when I started using it, over 250k!

Outstanding video on the topic.

I love the absolute correct info you share. I don't love imagining the looks of horrid confusion on many peoples faces, that are trying to keep up with you. They're still pondering on the 'early Ester formulations'. 'Who the heck is Ester!?!?!'