Hi Everyone,
I'm new here, and getting ready to dive into an oil change on what is to me a new car-a 1970 MGB.
The subject of oil for these cars has been beaten to death on MG-specific fora, and some searching here has lead me to some differing opinions and advice.
Many folks on the MG sites suggest Castrol GTX 20W-50, and the primary motive for this is the supposed ZDDP content. I've also received some conflicting information about it having been reduced.
Furthermore, I've read some linked papers I found in old threads here that discuss how important(or unimportant) ZDDP content is in flat-tappet engines like the B series.
So, before I buy oil for this change, I thought I'd ask here about what folks suggest. I drive the car frequently and usually for at least moderate length trips(often 60-80 miles) but don't thrash and also don't rack up a huge number of miles on it. Thus, I expect to be changing the oil more as a function of time than number of miles.
For some background information-the previous owner told me that he changed the oil shortly before he sold it to me(although since I don't know how long "shortly" is I'm getting anxious to do it myself despite the oil looking clean) and used Castrol 20W50.
The engine will reach about 65 psi within a 20-30s of starting up, and then drop to !50 psi at idle when warm and back up to ~60psi when at speed. This is consistent with a "good condition" B series engine.
So, with all of that out of the way, can anyone suggest an oil that would be a good match for this engine? The factory specified either 20W50 or SAE 30(for basically everything, including the transmission and the carburetor damping oil), so am inclined to stick with a 20W50 but am open to other weights if they would provide some real benefit.
I'm new here, and getting ready to dive into an oil change on what is to me a new car-a 1970 MGB.
The subject of oil for these cars has been beaten to death on MG-specific fora, and some searching here has lead me to some differing opinions and advice.
Many folks on the MG sites suggest Castrol GTX 20W-50, and the primary motive for this is the supposed ZDDP content. I've also received some conflicting information about it having been reduced.
Furthermore, I've read some linked papers I found in old threads here that discuss how important(or unimportant) ZDDP content is in flat-tappet engines like the B series.
So, before I buy oil for this change, I thought I'd ask here about what folks suggest. I drive the car frequently and usually for at least moderate length trips(often 60-80 miles) but don't thrash and also don't rack up a huge number of miles on it. Thus, I expect to be changing the oil more as a function of time than number of miles.
For some background information-the previous owner told me that he changed the oil shortly before he sold it to me(although since I don't know how long "shortly" is I'm getting anxious to do it myself despite the oil looking clean) and used Castrol 20W50.
The engine will reach about 65 psi within a 20-30s of starting up, and then drop to !50 psi at idle when warm and back up to ~60psi when at speed. This is consistent with a "good condition" B series engine.
So, with all of that out of the way, can anyone suggest an oil that would be a good match for this engine? The factory specified either 20W50 or SAE 30(for basically everything, including the transmission and the carburetor damping oil), so am inclined to stick with a 20W50 but am open to other weights if they would provide some real benefit.