All I know is Ive been using M1 for years. My Ranger doesn't like it. Its the only car / light truck Ive had that disliked M1. For some reason it likes to burn it and rattle.
So until some lab rats can tell me its for sure not the oil it use to be. I guess I will keep using it. I think its the best off the self oil available in my area. And I will keep running on the long OCI's
09 HCHII, w/Navi
07 Mazda3 S Touring, 5MT
Mild Hypermiler or Mad Man?
On second thought, is it possible you guys aren't cleaning your K&N's properly? I usually clean mine with every oil change. I'm pretty sure mine is doing its job, because during the winter time when there was a lot of salt dust everywhere, the thing would plug up and I'd have to clean it often.
Also, I'd have to double check, but last time I looked my wife's Saturn (paper filter) had more dust "on the wrong side of the filter" than mine does -- a very thing coating of fine particles down the length of the intake snorkel. I don't remember seeing that on mine.
I bone dry the car until I can put in atleast 13.5 gallons. Thats how I am calculating Miles per tank. I know I could just divide, but.......im lazy like that.
I can only comment on my experience with the K&N-I did research online and decided to try it.
I am running the prestone platinum synthetic oil at 5w30. Supposedly oil change every 75k. We will see.....
2005 Pontiac Sunfire
1991 Toyota Celica
Whoever wrote that about synthetic oil was wrong, that's all. Reduce friction, improve efficiency. That's well documented elsewhere. I use the thinnest synthetic I can get away with, in the engines, transmissions, power steering, rear end, etc, and that does work.
As for K & N air filter, that certainly isn't going to help mpg unless you happen to be replacing a badly plugged paper filter with it.
The very best Syn Oil in the world will improve MPG by only a slight amount, almost negligable, to be sure. I've proven it for myself, as have many others.
I've been splitting the difference between medium/low cost dino oil and high end synthetic. Been using WalMart synthetic, in the recommended weight for my car (10-30) it's about $3/qt.
I figure it's likely not as good as Mobil One or other top shelf synthetics - but definitely should be better than cheapo $1.50-$2.00/qt dino oil. FWIW. I used to change it out at 3K miles but I hope/plan to go 4K as long as it doesn't look nasty.
And change out a couple qt. of auto trans fluid at the same time, this gives me a rolling change of tranny fluid so I don't have to pay major $$ to change it all out at once. That way I think I can afford synthetic tranny fluid.
Currently getting +/- 50 mpg in fall weather. EPA is 31/39 so not too shabby. WAI, fuel cutoff switch, full belly pan, smooth wheel covers.