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Message: [QUOTE="Charles, post: 566707, member: 103"] What was the mpg that Brian pulled with the 400% nozzles in the DPC again? Wasn't it like 22mpg? Everybody put that in your bigger nozzles are less efficient pipe and smoke it, lol. If you push a nozzle to its MAX available time for a given power it will be INEFFICIENT. Such as asking a 30% to make 500rwhp. And there are points all in between where each nozzle overlaps another for a given power point in terms of which is most efficient. Problem is, pretty well this whole discussion (IMO of course) is hopelessly skewed far, far away from the [i]actual[/i] regions where these overlaps occur. For instance, a 30% nozzle is more efficient than a 200% EDM at and below certain power levels, and a stock nozzle is more efficient than a 30% nozzle at and below another level. Problem is, some people in this thread seem to be of the notion that this is all happening much higher than it is. It's not, lol. A 30% nozzle is probably more efficient than a stock nozzle from like 150 hp and on. Not 400 and on, even though a stock nozzle WILL make over 400rwhp, I've pulled over 420rwhp on them. But the stock nozzle was less efficient than the 30% nozzle all the way back at [i]maaaaaaaybe[/i] 180rwhp... The crossover from 30% to 200% is probably like 200hp IF THAT. I assure you that a 200EDM will run cooler and cleaner at 250rwhp than a 30%, even though a 30% will pull over 500 when pushed to the brink. This is EXACTLY why you find what we call "performance" nozzles on STOCK DT466 and 530 engines... The Navistar engineers understood through extensive testing that those nozzles sizes were most efficient for those engines making 250 to 300 or so hp. And then we take them and pull mid 5's on fuel way back when and over 700 on spray. The absolute MAX point of an injector should be oh so far away for a towing environment. What's so funny is that the sentiment that overshooting the nozzle size being for a performance oriented use and getting it as small as possible being for a towing use is perfectly BACKWARD, lol. It is in fact the towing use that needs the oversized nozzle that can deliver the required fuel quantity well below its maxed out flow, and the performance usage that can accept a nozzle that is pushed to the brink, smoking heavily and running hot because for a short burst those things are okay. We have that whole concept backward for the most part here... I would say if you haven't towed the driveline out from under a superduty or two yet.... you aren't [i]actually[/i] understanding this point as of yet. A properly set up towing 7.3 will see the driveline of a sub 650 ford in HELL before it ever breaks 1200 degrees. If you even have to GLANCE at your EGT gauge while towing flat to the floor for minute upon minute, upon hour, then you're NOT understanding my point. I'm just trying to clarify. These trucks towing around with say a 30% nozzle.... aren't even in the same zipcode in terms of capability with the exact same truck but with say a 200EDM nozzle that is tuned in to produce exactly the same wide open throttle EGT. EGT per EGT the 200% nozzled truck will pull so much more power. In a tow truck the EGT gauge should only be used for tuning purposes, or for catching a failure, like a blown boot or something. If you actually need that gauge to keep your EGT in check while operating the truck then you have FAILED. And you undernozzled the truck for the intended power goal. Period. [/QUOTE]