[MBZ] Group IV Synthetic (Was: Re: Block Heater)
Marshall Booth wrote: Group IV or IV/V synthetic oil (all the Mobil 1 oils are IV or IV/V mixes) will increase cold cranking speed by 30-50% and low minimum start temp by about 10 degrees (or a bit more) other things equal. Marshall, I'm curious if you've heard any of the rumors that Mobil 1 has quietly switched to a group III synthetic. It's been making the rounds on another message board I'm on.
Re: [MBZ] Group IV Synthetic (Was: Re: Block Heater)
David Brodbeck wrote: Marshall Booth wrote: Group IV or IV/V synthetic oil (all the Mobil 1 oils are IV or IV/V mixes) will increase cold cranking speed by 30-50% and low minimum start temp by about 10 degrees (or a bit more) other things equal. Marshall, I'm curious if you've heard any of the rumors that Mobil 1 has quietly switched to a group III synthetic. It's been making the rounds on another message board I'm on. There have been rumors that Mobil 1 has be switched to group III oils every year for almost 20 years. I expect that most of those rumors were started by people that made their living selling group III synthetics. It hasn't happened as of the last time I checked (about 4 months ago). All if the Mobil 1 Extended formulas are mixtures of group IV/V oils. As are the 5W-40 formulas. The formulas for the older Mobil 1 varieties are th3e same as they have been for years. Some of the lesser varieties of Mobil oils may contain group I, II or III oils - I have paid NO attention to them. Marshall -- Marshall Booth Ph.D. Ass't Prof. (ret.) Univ of Pittsburgh School of Medicine [EMAIL PROTECTED]
Re: [MBZ] Group IV Synthetic (Was: Re: Block Heater)
Marshall Booth wrote: There have been rumors that Mobil 1 has be switched to group III oils every year for almost 20 years. I expect that most of those rumors were started by people that made their living selling group III synthetics. It hasn't happened as of the last time I checked (about 4 months ago). All if the Mobil 1 Extended formulas are mixtures of group IV/V oils. After digging a bit and tracing links back through a couple of different forums, I found this, which seems to be the origin of the rumor: http://theoildrop.server101.com/forums/showflat.php?Cat=0Number=749606page=2fpart=1vc=1 Just shot some M1 EP 15W-50 into the Gas Chromatograph and was surprised to find it based mostly on mineral oil (presumably Group III) plus a good slug of AN. It may also contain a small amount of PAO, but so small that I can't be certain.
