Attached are oil analysis results for a 2006 Honda Civic LX with it's original R18A1 engine with about 260000 Km (163000 miles). There are two oil samples on this report. The first, earliest, sample is Motomaster Formula 1 Synthetic (available at Canadian Tire in Canada). The second sample is Pennzoil Platinum Ultra. Both oils are 5W20. The Motormaster Formula 1 synthetic ran for about 6000 KM. I changed it based on the maintenance minder. This oil was in the car from early fall to late spring last year (i.e. over the winter). I'm in eastern Ontario, Canada, so those were harsh, cold, winter driving conditions. A new Honda filter was used. There was no unusual service done to engine during this oil change interval. The Pennzoil Platinum Ultra ran for about 8000 KM. I changed it based on the maintenance minder. This oil ran from late spring to late fall of last year (i.e. over the summer). A new Mobil 1 filter was used. During this interval the engine was serviced as follows: i) new air filter at the beginning of the interval, ii) one treatment of CRC "One Tank Renew" at the beginning of the oil interval, ii) EGR valve cleaning, airflow sensor cleaning, throttle body cleaning at 1/4 interval, iii) valve adjustment (first in the engine life) at about 1/2 through the interval, iv) new Denso AFR sensor installed as preventative maintenance to replace the original 11 year old OEM sensor at about 2/3 through the interval. The car's fuel economy had improved by 5 to 10% by the end of the second interval based on the combined effect of the Pennzoil Platinum Ultra oil and the maintenance. I cannot separate the effect of each individually on fuel economy but I believe the improvement was substantially due to the AFR sensor replacement. The fuel economy improvement brought it back to the original OEM spec in Canada which is about 8.5 litre/100km (in summer driving conditions, without too much AC). I bought the car new and have all the service records. It never experienced a missed, or severely overdue, oil change. I checked the records and confirmed that it ran conventional oil, provided by a Honda dealer, for its entire life with the exception of one fill of Motomaster Formula 1 conventional (when I took over the service myself) just before the switch to the synthetics you see in the analysis report. The Motomaster Formula 1 Synthetic was the first synthetic oil used in the engine. The Pennzoil Platinum Ultra was the second synthetic fill. No oil sludge of any kind was observed under the valve cover when the timing was adjusted mid way through the Pennzoil Platinum Ultra interval. The timing adjustment was done to resolve a slight engine tick at idle. It runs quietly now and sounds almost like new to my ears. The car is a manual and does did mostly city driving, short trips, over both these intervals. I am very much open to feed back about the report. I don't have any experience reading these reports - I'm getting that now! Disclosure: I received the Pennzoil Platinum Ultra and oil analysis service as part of trial promotion provided by Pennzoil. That came about because I asked questions on a Pennzoil youtube video about some of their marketing claims. A Pennzoil rep. responded by asking me if I wanted to participate in the promo deal. That was about a year ago. I am totally independent from Pennzoil other than having participated in the promotion. Thank-you Pennzoil for the opportunity to participate. p.s. I'm visited this site many times in the past, but never joined and posted. Thank's to who ever runs it. There is a lot of good info here.