& there he is with more of his links he found on google! LOL! you should read your own links before posting, did you miss the part that says "older" vehicles mean prior to 1990?? thats 30+ years ago! is your 4runner a 1990?? & the "damage" they mention is only if you run low on oil & dont check it!!! synthetic oil itself does NOT cause engine damage, einstein!

Tips for Using Synthetic Oils in Older Models
When using the term “older” to refer to cars, it means those manufactured before 1990 or so. The risk with these models is that the seals, gaskets, and other components often aren’t as tight as with newer models. Because synthetic oil does a better job of cleaning out sludge, it could remove deposits that are acting as seals. This could result in leaks that cause the engine to burn oil and require you to monitor your oil levels and replace it more often. If you don't, you risk damaging the engine or other components.


It’s not accurate to say that you should never use synthetic oil in an older car. In fact, Castrol EDGE High Mileage is a synthetic oil designed specifically for high-mileage cars. If the car has been maintained and is in excellent running condition, the synthetic oil may protect the vehicle and prolong its life. Also, anytime you change from conventional oil to synthetic oil, always make sure to change the oil filter with every oil change.