Sorry for the very very long post.
Thanks so much for the feedback. Yes I am familiar with the diesel oil being blacker then gasoline oil due to the sooty content of the diesel, but I guess when its your personal car you are much more affected by the specifics LOL
I have a 1000 mile commute for my primary job that I do 1 - 2 times a month, so I have lots of opportunity to play with different things (ideas suggestions?) and see what it does to mileage but so far, I am completely blown away by the mileage this car is getting even without any mods.
I did put 65 series tires on it instead of 60 or 55 series so they are like 1/2 inch taller, makes Speedometer about 2-3 miles an hour slow so tiny overdrive and always run 44 PSI, so im sure that has a small effect at least.
It had a K&N air filter in it when I got it, but after reading through this forum I have taken it out and thrown it away and put a standard Mann back in it since everyone seems to poo poo the K&N on these drivetrains. Something about the filter oil messing with the mass air sensor or a sensor downstream somewhere? Makes sense. Besides the K&N was not as deep as the stock filter so the stock filter I would suspect actually flows better anyways.
I am using the Fram Gold oil filter currently, with a couple Mann on the shelf for later. The Fram Gold is rated for 10k miles, but I am going to run 5k for at least the next 2 oil changes I think. I know peeps will laugh at me for changing it at half OEM, but I have always been a little crazy about oil. Even on Fords that are rated at 6000 miles for oil, I still change at 3500 even with Full Synthetic. Maybe its wasteful, but its also the life blood of the engine and letting oil go through my engine with the same filter for 10k just makes me cringe. Especially on this engine since its so famous for its very high lifter pressures and cam wear issues even with the correct oil and intervals. Maybe its rated for 10k and goes 500k+ with those intervals, but since its so cheap on fuel you can afford to change the oil at 5K, so why not? Also I am thinking the Liqui-Moly oil additive is only like $6 with rebates and such, so im thinking of working it into every other or maybe even every oil change.
I might consider just changing the filter at the 5k mark and then the oil at the 10k mark, but I guess I will base that on how the oil looks and feels after this next change. 3 oil changes in 4k miles is extremely excessive I know, but since I dont know the history of the car I figure better safe then sorry and I am hoping that it will help flush out any crap and grungi-ness left behind from previous owners neglect. I cant see ever going the full 10k, but maybe 6000 to 7500 once I am comfortable with the drive trains health. (besides I enjoy changing oil, so...)
Just as an FYI - I have gotten on my 1000 mile commutes so far the following mileages (90% freeway and very flat roads) :
First trip = 47 MPG round trip
Second Trip = 44 MPG round trip
Third trip = 49 MPG round trip
Fourth trip = 45 MPG round trip
Fifth trip = I am on it right now, but the halfway point shows around 46
( have not broke 50 MPG yet, but very much plan too
)
I put the cruise on 80+ pretty much the whole trip so those are INSANE mileages considering the speeds im going. VERY happy so far and just want to keep the drivetrain as healthy as possible. These MPG are with the AC turned on, but that is a whole nother problem, the AC does not cool, so I dont think the AC compressor is taking anything away from the MPG at the moment.
Also - I am missing about half of the intake air box components. Didn't even realize it until I starting perusing this forum, but the primary air intake box is completely missing from the car. The air intake starts at the little duct that goes into the bottom of the air filter box. It points towards the passenger side and sits right in front of the driver side radiator fan. So basically the motor is eating hot air that comes straight out of the radiator fan and I am not 100% sure what parts are missing, but I know there are other air box components missing. However, since diesel engines get better mileage with warmer intake air temps anyways, I think I am ok with this arrangement for now since the primary purpose of this car is MPG. I mean we have all heard of a cold air intake, but what about a warm air intake for the MPG crowd LOL?
I also noticed the factory air box has a separating compartment in between the warmed exhaust air and the cooler intake air with a damper valve between them. Apparently the previous owner cut a small part of the partition away between them so the engine could breath through the entire filter all the time whether damper is closed or not, but not sure if that helps or hinders the MPG.
And finally thanks so much for your comments regarding the MISSING 2 quarts of oil. I will do some more research to figure out how to open this piping after the aftercooler (its NOT an intercooler since it comes AFTER the turbo
to see if it will drain out of there. I have actually done a little research into maybe putting a dry sump oil system on the car to make a seperate oil system just for the turbo bearing but I know that is a pretty extreme mod just for mileage since they are usually only done for very high horsepower cars. But the thought of having a couple quarts of oil that does nothing but lube and cool the turbo bearing and have its own filter is a very attractive concept to me. Hopefully the turbo is healthy and I wont need to swap it, but if I do, then at least I will know its history and be able to keep it healthy with appropriate oil and change intervals.
Bought the car at 133k, currently has 138k and I am very much planning to get 500k+ out of it...
Thank you thank you thank you for any and all comments regarding the lifespan and health of this very cool drivetrain. Cheers