Mackpro

Mack used to say 36" between the trailer and truck but 40" seems more realistic ( look at a UPS truck going down the highway, really close). Adding of thoses aero fairings that bolts to the bottom of the front bumper would also help. Between 1992-1994 we sold 50+ CH sleeper trucks to a fleet, when the MPG didn't meet what they were promised we added large roof farings with 12" sleeper extensions and this alone put them into their target MPG range. There used to be a Mack engineer (cant remember his name)that had a great list of goodies to set a truck up for MPG,you could call him up direct and discuss your specific set-up, sadly most all thoes great engineers were replaced by Volvo guys. Since Volvo took over I have yet been able to talk to a engineer.

Different turbo and injectors in the two engines. You might be able to turn the 460 down to a 427 with nothing more than a download. Most all ASET AC engines are exactly the same, just different turbo, injectors and download change the HP level.

Check the muffler, I spent a day on a lowpower complaint and after checking everything I could think of I climbed up a ladder and with the engine running I could cap off and hold the exhaust back with my hand. The baffle had come loose and was stuck side ways inside the muffler.

Here are things we do to try for top MPG on ASET's , adjust the valves(and jakes) and install new rocker arm hold down bolts( due to possible breakage), replaced the boost pressure relief valve on the intake manifold ( if you havent already replaced it), load the newest software and datafiles in both ECM's ( step 12B as its called ), calibrate throttle pedal and VGT turbo, pressure test the complete intake system including the EGR cooler piping, replaced the muffler with a Walker straight through muffler ( still quite), make sure there are coolant shutoffs on the fuel heater for summertime (keep them closed till it gets real cold), Figure out what MPH you want to run/cruise and talk to a good salesman how knows all the fourmulas for getting the correct tire size for the rear gear ratio and trans that you have. Sometimes a simple tire size change (without changing wheels) can get you into the "sweet spot" you to be for best MPG. We have seen trucks that were spec'ed correctly to begin with but the new customer wants to be like all his bullhauling buddies and went from 22.5 lo-pro to 24.5 full size just to be cool, but didn't realize he just screwed up his sweet-spot and now has low power complaints. Get low rolling restiance tires if possible. Make sure the hole in the hood meets up with the air filter housing ( marking paint on the rubber bellows and close and latch the hood) a good seal so it's not sucking hot air off of the engine in the summertime. Some of those aftermarket chrome hood louvers restrict to much air on the higher HP engine( says on the package). And of course dont be running 80+ MPH, keep it as slow as you can sainly deal with. Some guys say changing the governer setting (in the ECM) to all-speed instead of min-max helps the MPG and I have seen it help once but the guy was already a slow and steady driver so not totally sure on that one. Thats all I can think of for now but I'm sure I'm leaving somethings out.

Didn't see that, what about over-tourqued injector hold downs, I have seen guys tighten them with a impact gun and collapse the injector body and they wont spray right? But I guess that would happen right after engine start up.

Haven't seen to many 2004 and up AC ASET EGR engines that get any better than 6.2 mpg. I am working with one guy and we got him at the 6.0 point, just added a high flow Walker muffler and waiting to see the results. There is not just one thing that makes a truck get good MPG it's a combination of many different things that get you there.

Check the air compressor air intake tube that run around the back of the engine to the back of the intake manifold, the short rubber hose could have blown off, it happened to me.

Duralit is the way to go but for small leaks like you had we have some epoxy we use that works good. But if you got the money go ahead and do the Duralite and be done with it.

I vote leaky liners especially if the engine had no coolant filter on it!

It is possible (sometimes)to unplug the speedometer sensor and the truck will run wide open MPH, however most owners/companys who have their road speeds turned down have the MPH sensor tamper settings enabled. What this means is if you unplug the sensor/tamper with the adjustment or any fault occurs with the MPH sensor it will derate the HP and you will be worse off than just leaving it alone.

Thanks!

Thats it, cant seem to find it to buy or download.

Just heard a new song that started out talking about a red Mack Truck, something like "Chickenlights and Chrome" anybody heard it? If so who sings it. I heard it on XM radio Nsahville station. It was pretty good.

On the injector cup issue there are now stainless cups and new style injectors that come in a kit from Mack that will hopefully cure the cup issue. On the gasoline deal, all these trucks were dump trucks that were working in an area far from truckstops, these gas stations would have 4 pump handles on one stand, 3 grades of gas and then diesel. The diesel should have a black cover on the handle/nozzle but we found some stations would have green covers on the handles like the gasoline. The drivers just weren't paying attention.

There is a Mack service bulletin on injector fault codes, dont see many injector failures but mostly the wiring harness connectors at the injectors loose connection. We install new connector ends and this seems to fix the malfunction code most of the time. However as Rasler said the injector cups can cause issues as well. Also check the fuel tank for gasoline! We have had 4 trucks in the last 2 months that had gas in the fuel tanks and 2 were MP's and caused injector codes.

Last I could find of the E6 was in 1990 however in 1991 it still listed EME6-250L and 350L plus the EE6-350, I think these were for export.

Guess I will have to leave my phone in my tool box at lunch if I want to keep going to the strip club!

I agree Rhasler, while Mack/Volvo says their broke and no money to help (policy/goodwill) a owner/operator who has bought an MP-8 and is on their 3 set of injector cups. Volvo show up with this rig, while I like it and it's cool, I too think Mack should use the money to help stand behind their product!

Sorry to hear that! I'll talk to our sales guys. I known your situation and praying for you and your family!

The oil cooler inlet screen could be plugged, needs to be removed and cleaned or replaced every year or so. oil cooler inlet screen.pdf