This is an interesting thread although I see no surpirses. I do have a couple of comments.
I agree with Too Slick that many short trips with frequent warm ups (regardless of ambient temperature) would be a tougher test on the oil than the apparent 24/7 operation that Mobil's testing seemed to be.
Despite that, I tend to agree with others that the Vegas Taxi application can be pretty tough. Lots of ambient heat and lots of idling are tough situations for oil. Plus, Crown Vics are pretty tough on oil based on my testing. I eat up a batch of Amsoil in about 18,000 miles over six months in Florida heat in my Crown Vic. While Mobil's report did not say, I am assuming the taxi test was done in Crown Vics based simply on the % of cabs that are Vics.
Another observation, the taxi test report did not state how much make oil was added over 15000 mile intervals. The achilles heel of the Crown Vic 4.6 is poor valve guide design that can cause fairly high oil consumption (Ford claims one qt per 800 miles is acceptable consumption on the 4.6). Plus, Mobil-1 is not particularly well known for its Noack volatility and resultant lack of consumption. So, for all we know, they may have added 6 quarts (or more)of make up oil over their 15,000 mile drain intervals. Is is possible that the make up oil just might have had soemthing to do with thier ability to "hit the jackpot"?
Finally, I applaud Wullmaster for his observation on viscosity thickening. Per his comment "I couldn't conclude there was any significant difference in viscosity over the interval." I did not notice this per se but I did notice another trend in the 3mp test. That was, the Mobil-1 and Amsoil thickened on almost identical linear slopes. The Amsoil simply started closer to the 40 wt. mark.
That's my $0.02 on an ongoing interetsing debate.
I admit to being a bit skeptical of the slant the Mobil PR people may have put on this report and as such (and as an admitted Amsoil fan), I tend to discount it. I came to this site today figuring that sooner or later we'll see some more meaningful, objective real world results on these new products. I did not see much objectivity here but in time I am sure we'll see more data.
Kudos to Mobil for finally stepping up to the plate on long drain intervals. Shame on them for claiming it is their novel new idea.
Don
I agree with Too Slick that many short trips with frequent warm ups (regardless of ambient temperature) would be a tougher test on the oil than the apparent 24/7 operation that Mobil's testing seemed to be.
Despite that, I tend to agree with others that the Vegas Taxi application can be pretty tough. Lots of ambient heat and lots of idling are tough situations for oil. Plus, Crown Vics are pretty tough on oil based on my testing. I eat up a batch of Amsoil in about 18,000 miles over six months in Florida heat in my Crown Vic. While Mobil's report did not say, I am assuming the taxi test was done in Crown Vics based simply on the % of cabs that are Vics.
Another observation, the taxi test report did not state how much make oil was added over 15000 mile intervals. The achilles heel of the Crown Vic 4.6 is poor valve guide design that can cause fairly high oil consumption (Ford claims one qt per 800 miles is acceptable consumption on the 4.6). Plus, Mobil-1 is not particularly well known for its Noack volatility and resultant lack of consumption. So, for all we know, they may have added 6 quarts (or more)of make up oil over their 15,000 mile drain intervals. Is is possible that the make up oil just might have had soemthing to do with thier ability to "hit the jackpot"?
Finally, I applaud Wullmaster for his observation on viscosity thickening. Per his comment "I couldn't conclude there was any significant difference in viscosity over the interval." I did not notice this per se but I did notice another trend in the 3mp test. That was, the Mobil-1 and Amsoil thickened on almost identical linear slopes. The Amsoil simply started closer to the 40 wt. mark.
That's my $0.02 on an ongoing interetsing debate.
I admit to being a bit skeptical of the slant the Mobil PR people may have put on this report and as such (and as an admitted Amsoil fan), I tend to discount it. I came to this site today figuring that sooner or later we'll see some more meaningful, objective real world results on these new products. I did not see much objectivity here but in time I am sure we'll see more data.
Kudos to Mobil for finally stepping up to the plate on long drain intervals. Shame on them for claiming it is their novel new idea.
Don
