Since the crazy Mobil 1 Synthetic deals (5 qt + filter for ~$20 after MIR) seem to have dried up, which synthetic has good cost/performance for extended intervals on an 06 Acura TL (at 90K)? I only drive about 5K/yr, so I have been running extended time intervals (usu ~12 mo, but did an 18 mo interval once). The OCI computer recommends ~7.5K, regardless of time. On dino oil (have tried Pennzoil, Shell, whatever Acura uses in their dealerships), I only get about 3-6 months (despite the low mileage), before there's mild surges and decelerations on upshifts and downshifts in normal driving conditions. With Mobil 1 Synthetic, I can get 9-15 mo before these symptoms start up. At 12 mo on Mobil 1, the oil is brown/amber and not black. In the last few years, I've been using Mobil 1 Synthetic (not Extended Performance) or the Synthetic High Mileage randomly, and oil consumption is < 0.25 qt/5K with no noticeable leaks. I used Amsoil once in the past and drove 10K in 1 yr before the changing it out, but it did not have any of these symptoms at time of change. I've been eyeballing Red Line, since its highly recommended on Acurazine, and hoping for an experience as good as Amsoil, but since Red Line is expensive, I'm also considering a name brand mid-priced synthetic (eg similar to Mobil 1) on a good deal. For example, Castrol Edge Extended Performance is on sale at Walmart for $18/5 qt and seems to be well regarded here. Probably with a $10 Mobil 1 M1-104A oversized filter (or the spec designated M1-110A). There are a lot of mid-priced synthetics, and I can't really tell the difference between them. Any other deals on a good synthetic oil +/- filter that I should consider? --- If it matters, I'm using Red Line Lightweight Racing ATF (Type F) with Red Line D4 ATF (65%/35%). In the past, I have tried Amsoil OE Fuel Efficient Synthetic ATF, Castrol Transmax Import ATF, as well as Honda OEM ATF (probably Z1), with no differences in experiencing surge/deceleration symptoms at extended oil life.