Synthetic motor oil

I have just changed my oil to synthetic,then a friend told me that some cars are not suitable & also I cannot change back to regular oil.Is that true?


Ask your friend for the information she/he is quoting. Say that you’re interested in reading it. Then do a little research of your own.


Sorry…but your friend is 100% WRONG…

ALL engines that can use regular dyno oil can use Synthetic oil.

There are SOME engines where you should only use Synthetic oil. Turbo charged or super charged engines should use synthetic (there are others).

As for going back to dyno…sure you can…You can go back and forth…and even mix them any way you want.

Dino and synthetic oils are chemically exactly the same stuff. The only difference is that synthetic contains fewer impurities and its molecular size is more consistant. These differences make it stand up better to heat than dino, and allow it to flow more readily at extreme cold temperatures than dino. It’s thus used in cars that subect the oil to extreme stresses, such as those with turbochargers. Turbochargers operate a high rpms and the oil is heated by the exhaust as it lubricates the turbo bearings. Those cars’ owner’s manuals will specify synthetic.

Unless your owner’s manual specifies synthetic as a requirement, you can switch back and forth as you like without fear of problems.

I use synthetic in my Yaris and it isn’t dead yet. People will tell you anything about cars. It’s the only fantasy field where everybody is an expert, except for sports, history, physics, geography…

"It’s the only fantasy field where everybody is an expert, except for sports, history, physics, geography… "

Add to that politics and high-end audio equipment.

Don’t forget law.

While synthetic may not be any better than regular oils, it is always at least as good as regular oils. Note: synthetic or regular, it must meed the specifications listed in the car’s owner’s manual.

The reverse is not true. If you car specifies synthetic, you should not use regular oil in it.

ABSOLUTELY NOT TRUE! Full Synthetic is the best and worth the extra cost!

I use a high quality full synthetic Race Engine Oil “Red Line” Brand (Amazon) 20W50 in a '86 Landcruiser with 317,000 miles and original engine. It shows! Better mileage, 155 psi +/- 2 psi compression on all six cylinders! I change oil and filter once a year and it keeps on going and going…

dorcom1…You will find people here with well past your 317k miles using nothing but regular dyno oil.

I’ve had two vehicles go past the 300k mile mark on nothing but conventional motor oil. Sold one to a neighbor…and she sold it at 450k miles.

Better Mileage??? NO…That’s been proven that any mileage difference is insignificant.

Personally I use full synthetic…for 2 reasons…The cold winters here in NH…and because I tow a camper around many weekends during the summer.

I had an '89 Toyota pickup that kept going and going until it got totalled at 338,000 miles. I had a '79 pickup that kept going until it rotted in half in the middle of the road. I gave it to the local boneyard owner who bolted the bed to the cab with a 2x4 between them and kept driving it as a yard truck. Both only saw dino.

The truth is that in over 40 years of owning cars I’ve used only dino and have never worn an engine out. I recognize the value of synthetic for high stress applications, I’ve never seen any evidenciary data that shows that it entends the life of a naturally aspirated engine. Pending that I’ll stick with dino, but I’m glad you’re happy wit the synthetic.

Since manufacturers are turning to turbochargers more and more frequently to satisfy EPA requirements, it’s possible that we’ll ALL end up either driving EVs or using synthetic soon anyway.

155 psi is rather weak.