A_Harman is correct in what he says about WVO (waste vege oil) setups, and mine is no different. 80gallon coolant heated in bed tank, coolant heated Davco 382 fuel filer, Fass HPFP @75psi fuel pump, purge solenoid to clear the heads of WVO before shutdown, and finally a 30in Arctic Fox thermalliner stainless tube in shell coolant based fuel heater. I switch to WVO at 140-150F based on the engine oil temp gauge I have on the Scangauge 2. Coolant temps are about 2 degrees cooler than the oil temps reported, and I've just been to lazy to install a seperate coolant temp gauge that is accurate, the one in the Scangauge xgauges does not report accurately on the 7.3L's it seems, and for that matter right now I can't even recall where the coolant temp sensor is even located on the 7.3L. Most digital combo gauges have you tap the oil temp wiring cause it's more accurate for gauging engine temps.
When I start up or shut down, I am on 100% ULSD or 90% ULSD 10% k-1 kero as we still can get low sulfur kerosene round here. The 10% kero (3 gallons or so) mixed in with the diesel puts back some of the sulfur the engine/injectors were designed to have. Might be my imagination but I swear the EGT gauge i have stopped showing random spikes like 1500F soon as I started adding a little LS K-1 in. For some odd reason the spikes were not there back a few years ago when you could still get 500ppm LSD at truck stops. anyhow i digress... shutdown on diesel is roll into my driveway on WVO, flip the diesel pump back on, turn WVO pump off, flip purge solenoid switch on for a 12 second count pushes about 16-20 ounces thru the fuel rails in the heads and back down the WVO fuel feed line. Idle truck for a minute, then shutoff. Usually takes 30 seconds for my EGTs to drop to the low 300's which before I did the WVO system was my "turbo cool down" before shutting off the truck. I have a remote starter that I need to wire in at some point that has a turbo timer built in and that would automate the cool down, and after purge idle for a minute to make sure all the WVO is out of the fuel passages in the injectors.
dnewton3 - yes most of the time the temps are fine around here that a 10w30 would be fine, year round even, and you are correct about the 15w40 shearing to a 30w in a HEUI system. Only reason to run 15w40 at all is that I usually jump in once a year when Mobil has their Delvac rebate deals. Means I get a good oil for 3 seasons of use without problems for ~$7-9 per gallon depending on the price on the shelf. Call me cheap, but I normally buy enough to max the rebate and have 2 15w40 oil changes on the shelf. I do occasionally spend time overnights in places colder than my home area, but even still the coldest nights (which are rare anyway) at usually not ever really lower than -5F. There is a HUGE difference in start up ease/speed when going to 5w40 for the winter, 10w30 seems to be almost as good, but 5w40 is really noticeable, ad like i originally was asking, I had 1 gallon free, now I have 2 gallons of 5w40 that cost me a total of $3 and a trip to WM, and I'll be blending that with the 10w30 I had previously picked up last time I saw it at a WM i was in. Of the WM near me, 1 sometimes has the 10w30 white bottle rotella in stock, and none ever seem to have the T5 10w30. Course if I drive 40 miles to a WM out by a friend of mine in Cobleskill, NY, they have the dino Rotella 15w40 & 10w30, the T5 10w30, and the T6 5w40, always stocked, but it's alot more rural out there and I imagine that there is more demand for the different weights. Pretty much the only time I need some 10w30 is the late fall/early winter oil change, so its a one time a year thing. This year money is tight for me at the time I needed to do the oil change. Before posting this thread I was considering taking 4 new jugs of Delvac 1300 15w45 back to WM to get store credit to put towards 2 gallons of 5w40.
Those really cold snaps that happen randomly, like last years couple nights -17 and -10 nights are statistically rare as you point out. Even when cold like that I'm not worried about damaging anything in the engine so much as going lighter weight oil really aids in startup and keeps the injectors happy (not screaming) from the cold cold oil. between the 200 or so amps the GP's suck out of the batteries, cold thicker oil, and turning over that engine, in the really cold statistically rare days it's comforting to know that I won't have a problem with quick starts to well beyond what the normal lows are.
As to the "spent" aspect, with the shearing of the HEUI system, one of the first signs it's time to change the oil is when you end up with bubbles in the oil on your dipstick. New oil till about almost 5k miles (depending on what you are using the truck for, towing heavy all the time seems to chew it up faster) you start getting bubbles from anti-foam agents breaking down in the oil. In any none HEUI system this wouldn't be a problem, but ar in the oil makes for fun when that oil is pressurized 500psi to 3200psi and fed to the injectors. Any PSD owner that works on thier own vehicle and has done anything where they open up the HUEI system will attest to the PITA air in there can be. Injectors won't fire fuel if there is air in there, which will eventually work its way out, but till it does you get missing and loud injectors. Also when one changes the oil on a7.3L PSD you miss the 2-3qts of old oil that is in the heads and HUEI pump reservoir, that oil cycles thru the engine and is mixed in with the new, but without going thru a time consuming process to get most of it out, you are already starting the new OCI with 1/2 a gallon or more old oil in there. This is why a PSD with a fresh oil change whil have the oil going black or at least much darker in a matter of minutes after starting up to check levels.
At some point I plan to buy and install a Webasto diesel fired parking heater to use as a coolant preheater, but thats a $700-800 investment I haven't budgeted for yet. But at 0.1 gallon of diesel to warm my truck to 150F in an hour, means I get on WVO almost immediately when I jump in and start the truck up. Currently via idling with the Ford add on idle controller and the exhaust back pressure warmup valve, it requires 15 min at 1200rpm to get me to 150F, in the winter. that uses about 1/3 a gallon of diesel, of if I just drive to warm up before switching to WVO I usually have to go about 5 miles, using around 1/2 to 3/4 of a gallon to get to WVO use temps. As it is I like to give the truck at least 5 min minimum to warm up from a dead cold start in the winter.
Course if I ever had the time and money to do it, I'd just have a WVO fired boiler in my garage (which my truck cant fit in anyway) and I'd use a domestic hot water coil to heat coolant to feed some quick connects on the front of the truck, that way the block would always be warm and I'd use almost no diesel....but that is going a little overboard, but would be a fun project to putz around with.
