Originally Posted by nearhomeless
Narrowing things down in my bus search.
I know there is a best engine thread I started, and also a mileage thread but the mileage thread doesn't say what engine you had so..
I'm hearing people with Cummins 5.9 and Cummins 8.3 report 10mpg or above so far. Is there anyone getting lower mileage with those engines? Is anyone with other engines getting 10mpg or better? Please post, I want to see how common these observations are, and under what conditions. (speed, hills, loads) I kept telling myself "well I dont plan to drive it much at all" but if I plan to put 10,000 miles on it over the next few years, that alone would pay for a $2000-4000 difference in fuel or even a whole 'nother backup bus.
So this is JUST for people getting 10mpg reliably at highway speeds (55mph counts), what is your engine?
I'm a commercial driver (Owner/operator) of a 1999 Freightliner. My first engine, a Cummins ISC is just now being retired after 700K miles. I expect to get even more from my new Cummins ISL.
Due to my going back to work full time, I have a skoolie for sale. ***** email@example.com
for complete details.*****
The major increase in mileage with these vehicles has been in streamlining and weight reduction, as well as decreasing internal friction with the use of synthetic lubricants and KEEPING these lubricants CLEAN.
Horsepower is horsepower and NO manufacturer (despite advertising nonsense) has the magic formula for getting more btu's from a gallon of fuel than anyone else.
Again, No one really gets more "go" from a gallon of fuel than anyone else.
Many who claim otherwise are self DELUDED to make themselves feel good.
That being said, the older 4.53, 6.53, 6.71 and 8.71 (two cycle/ two stroke) Detroits really gobbled the fuel but you'll never see one of these in a skoolie. These supercharged, two stroke engines had a "power stroke" everytime the piston came up. Just like a really big dirt bike. These engines are dinosaurs and are seldom seen in modern vehicles.
Decreasing a vehicle's weight and decreasing WINDAGE is another way of increasing mileage.
To "keep up" with the cars on hills, requires the average Big Rig to have a 600hp (3406 cat, Detroit series 60 or Cummins ISX) 2500 pound engine and 600 pound ten or thirteen speed Eaton tranny.
To whit: SPEED is MONEY and it costs, no matter who you are or what you're driving unless you're on a test track somewhere.
Decreasing an engine's INTERNAL friction by using synthetic oils is another way of increasing mileage.
One of the above mention engines costs $500.00 to fill'er up with Royal Purple or Mobil One synthetic PLUS filter(s)
Thats why "super filters" like Puradyn and centrifuges like MY skoolies spinner II are so popular.
The oil is cleaned, NOT thrown away every so often.
The engine's cooling FAN can cause "parasitic" losses up to (50) FIFTY horsepower just to cool the engine at
lower speeds. Waterless synthetic oolants like Evans Coolant can allow the raising of the fan's thermal clutch cut-in
temperature to keep the fan off longer and so save money...fuel.
There's not much can be done with a bus/ skoolie except KEEP YOUR SPEED DOWN.
Pushing that Big, Blunt windshield down the highway at 65-70 mph is gonna cost you, whether you're drivng a bus or a Kenworth. The newer rigs are much more streamlined than the older rigs were, with big radiators and lots of chrome.
The Classic Pete's and Kenworths sure looked pretty, but at a cost.
Diesel fuel in the 60's was 20 cents a gallon so who cared about fuel milage???
Keeping the speed down 55-60 is good medicine for both buses and Big Rigs.
******** Unfortunately, the newer and more streamlined buses also come with Electronically injected (work of the devil) engines, that can be a nightmare to work on and fantastically expensive to buy parts for. Stay away from these*********
Get an older bus with a MECHANICALLY injected engine for durability and longevity. You cant hardly kill one of these older engines.
A small amount of water in a sh_tty factory fuel filter can cause the ruination of thousands of dollar worth of electronic injectors as the micrscopic bits of water FLASH into steam upon ignition and erode the injector tips.
Pri-D is GREAT for keeping the exhaust smoke to a minimum. Its the only thing that reliably works.
I can get parts for my 1987 International 6.9l engine for "peanuts" compared to the electronically injected models and do ALL the work on it myself and save BIG bux I can tell you.
A complete set of (
eight NEW, not rebuilt, MECHANICAL injectors can be had (Stanadyne or Delphi) for less cost than just ONE rebuilt electronic injector.
Injectors for my Freightliner's ISL Cummins are $600.00 EACH (exchange) .
They cost even more without a USABLE core for exchange.
After buying an OEM mechanix guide for this 6.9L engine, all is easily fixable with simple Sears Hardware tools and a little patience.
Unless you have a laptop computer and an OEM factory program to "talk" with the engine's ECM, and a bundle of money
to spend for parts, stick with the older skoolies and have some fun. Thats what skoolies are about.
Let the civics and the rest of the worlfd "blow" on by on the hills. They aint really going anywhere.