JHZR2
Staff member
These are my results from my BMW. The last two UOAs have been continuous, with Shell Rotella Synthetic 5w-40 being used. I have used LC at the 10z/qt rate and then ~2oz/1000mi. Ive also used FP at 2oz/10 gal, though a few things should be noted that are important:
-I used MMO a few times during this OCI, once at a very high shock dose where I got low MPG as a result (It was about 8 or so oz. per 10 gal).
-In the last 1200 miles, I added a bottle of Auto-rx for cleaning. The car appeared to idle a bit better than it did previously, but there was no MPG improvement or anything else. I did not add LC when I had the ARx in the crankcase, though residual was likely still there.
The car passes HC/CO/CO2 emissions fine, but fails NOx on the NJ dyno test. I get 27-29 MPG regularly, in mixed driving. The oil that was in the car during the last emissions test was the previous rotella OCI, where the results were quite good. Id guess that either there was some significant problem with ARX and LC in combination, resulting in the reduced viscosity and increased wear numbers.
It should also be noted that in the gap between the older two OCIs and the two rotella OCIs, the same rotella Syn oil was used, so viscosity retention was not a function of remaining 15w-50 M1 in the crankcase.
I find the oxidation number odd (I copied this right off of the website with my results. Nitration seems normal, though higher than last time, when LC was used the entire interval. Sulfation is also higher than normal, though I cant say what that means.
I have to wonder if the MMO used caused the viscosity drop... Especially since it has been tested againa and again that LC and ARX do not effect viscosity. I wish I had a fuel dilution number, as that might give some insight, but the car runs the same, and the use profile has been the same, so I dont see a reason why in summertime driving, fuel dilution would have gone up...
-I used MMO a few times during this OCI, once at a very high shock dose where I got low MPG as a result (It was about 8 or so oz. per 10 gal).
-In the last 1200 miles, I added a bottle of Auto-rx for cleaning. The car appeared to idle a bit better than it did previously, but there was no MPG improvement or anything else. I did not add LC when I had the ARx in the crankcase, though residual was likely still there.
The car passes HC/CO/CO2 emissions fine, but fails NOx on the NJ dyno test. I get 27-29 MPG regularly, in mixed driving. The oil that was in the car during the last emissions test was the previous rotella OCI, where the results were quite good. Id guess that either there was some significant problem with ARX and LC in combination, resulting in the reduced viscosity and increased wear numbers.
It should also be noted that in the gap between the older two OCIs and the two rotella OCIs, the same rotella Syn oil was used, so viscosity retention was not a function of remaining 15w-50 M1 in the crankcase.
I find the oxidation number odd (I copied this right off of the website with my results. Nitration seems normal, though higher than last time, when LC was used the entire interval. Sulfation is also higher than normal, though I cant say what that means.
I have to wonder if the MMO used caused the viscosity drop... Especially since it has been tested againa and again that LC and ARX do not effect viscosity. I wish I had a fuel dilution number, as that might give some insight, but the car runs the same, and the use profile has been the same, so I dont see a reason why in summertime driving, fuel dilution would have gone up...
