5w-20 / 5w-30 / Synthetic

I've got two questions regarding engine oil

First, the car manual says to use 5W-20 engine oil, what difference does it make if I using 5W-30 instead?

Secondly, is it true that if you start using synthetic motor oil, you can't switch back to regular?

no i wont make a difference if you switch to 5w 30.
no that is not true about synthetic oil, if you use synethic oil you can switch back to regular oil any time. thats what synethic blends are, synethic oil mixed with regular oil

The reason many automotive makers recommend 5w 20 is to meet fuel economy guidelines. I have used synthetic oil for a long time in all my vehicles In fact I had a 1996 honda civic that I traded in, in 1999 it had over 70+ thousand miles and by using synthetic motor oil I changed the oil only 2 times in the 70,000 miles. Its that Good. The motor oil I use is a 0w-30 in all my vehicles with a recommend drain interval of 35,000 miles.

Originally posted by lapspec
The motor oil I use is a 0w-30 in all my vehicles with a recommend drain interval of 35,000 miles.

why?

lapsec i hope you were kidding?i dont care how good oil is twice in 70,000 miles i cant believe that...


gunnmen01

Gunnmen 01, No I was not kidding. It actually convinced me to become a dealer of Amsoil synthetic lubricants. You may think I am crazy. However, I wanted to test Amsoil out to see if it does what they claim. I started using the 0w-30 at about 2700 miles. I did an oil analysis at 21,200 miles and found the oil good for continued use. I then resampled at 34,000 miles and the report stated to just change the filter. At 43,554 I retested and was told to change the oil due to water containation and viscosity increase. I Then Changed the oil and did the last Oil analysis at 68,921 miles with 22,941 miles on the oil. once again the Oil was suitable for continued use. these are the results I have had personally. I will soon publish the full Oil analysis sheets on my web site www.synthetic-lubricants.com. You could read them for yourself there.
Thanks for responding and your concern
George

I Posted the results on my site here is the link .
http://www.synthetic-lubricants.com/news.htm