Average 16-17 at 75mph, 14-15 city driving.

Best ever was at about 60mph got 19.8mpg on a full tank.

All stock, 220K miles.

 

I tried the 2 cycle oil for 2 reasons. I read about it tested in Diesel Power and also in the 7.3 forums on this site. It essentially adds lubrication to the injectors from what I remember.

 

The 2cycle oil is to provide lubricity for the injectors. Our 7.3s were not designed to run off ULSD and the injectors can suffer even though additives are supposed to be a part of the formula to cover it. When's the last time the gov't truly covered your butt? Even if it didn't add any MPGs, I'd add it to help my engine run smoother and the injectors to last a bit longer.... a good bit longer.

 

I wondered about this ULSD. So, how much 2 cycle oil are you running and where exactly are you putting it, in the gas tank? And how often?

 

I am using the $2.00 Supertech from Wal Mart. 1 16 0z per fillup. And yes, directly into the fuel tank at each fill up. As I understand it, that may not be enough. If I recall, some guys are running 1 oz per gallon.

 

So what, specifically, is in the 2 cycle oil that helps the injectors? Or what does the ULSD not have that our engines are wanting? I am just trying to understand what problems the ULSD can cause and why and what 2 cycle oil does to prevent it. Regardless, I think I am gonna stock up on some of this stuff. Thanks,

 

It's cheaper by the gallon at Wall Mart. What you want is the Outboard motor oil TC-W3. Most put 1/2 ounce per gallon.

 

OK, SC boys - whats with the 2-stroke oil?

Why?

Any proof behind this theory?

 

i dont know SC-Ex, thats what Im trying to find out.

 

It's not a theory. There's plenty of data available on the 'net.

Some guys use 2 stroke oil because it's convenient. Some guys use name brand additives. It's all personal preference.

There was a chart that made the rounds a couple years ago that ranked the different additives for lubricity. I didn't save it but if you do a search over in the 7.3L forum you'll get a ton of reading on the subject, and will probably come across the chart.

Stewart

 

I have an 01 7.3 4x4, X. I bought it @ 100k miles i have put 11kthe miles on it the only thing it tows is my fam. All my trips are @ least 60 mi. round trip i drive lite on the foot top speed 65mph however my fuel mileage is 13.5 to 14.5 my tires are 285syou the mods are 6637 airfilter, bigboost, edge programer i use setting 3. All this and no change in mileage.
what else can i do??
I am thinking 4in exhaust and electric fan maybe??

 

Wow, old thread. I sure have learned a lot since I posted here 2.5 years ago!

Anyway, since then, I have averaged around 16 in town, 19 hwy, 14-15 when towing.

How much air in your tires? If they are load range Es, you should be running them at about 70 psi, that could help mileage. Also, your EBPS (exhaust back pressure sensor) tube could be clogged. That can hurt mileage. Also, how are you calculating the mileage?

 

Calculating by dividing total miles per tank by gal added @the fill up
going to clean the ebps on Saturday

 

My mileage improved by about 2 mpg switching back to stock sized highway tires from 285 all terrains fwiw...

 

My mileage went up from 15 to 16.8 consistently around town just by re-ringing the injectors after 185,000 miles. Had 3 blown O-rings and had no signs. On the highway, 19 and have seen 21 twice, all hand calculated. I have a Diablo economy/tow tune on mine. Otherwise all stock.