2005 Mack Vision

[bryan723]

Hi, was looking around last night and came upone this site and thought I would join and see if anyone can help me figure out what to do with my truck. I bought the truck new back in year end of 2004 and previous truck was a 2000 mack vision. Had good success with that truck so figured would trade it for a new one. Well was told the truck should get 6mpg, a little less then what I was getting with the 2000 model, but only way I have gotten close to that is to bobtail. Pulling loads I am 4.5 to 5mpg, depending on weight. So I actually bought a used fld120 with a detroit in it 3 years back and have been driving that and letting the mack sit. I kept the mack because 2yrs left on payments at that point and didn't know how long the freightliner would last, plus I was saving more in fuel then what the two truck payments together were. Anyway the detroit needs an overhaul now so am back to driving the mack. Fuel mileage hasn't gotten any better sitting there. I like look and features of the truck and how quiet it is going down the road but spending $20,000 to $30,000 more in fuel a year doesn't make sense even if the truck is pd for. So has anyone done anything that has improved their mpg? Was seeing some posts about a plate to block the egr sensors and keeping the hot exhaust from going back through the engine again? Or could I just rebuild the detroit and put that into the mack truck so I could get back to the 7-8mpg range? Just trying to figure out some options at this point because being an o/o I need the most efficent truck I can get. I know the cheapest route would be to just rebuild the detroit and put back in the freightliner but that truck is old and noisy and figure since out on the road would be nice to have something quiet to drive and a bit more comfortable. Thanks.

[Bobby Covert]

I am by no means a mechanic, but you have failed to mention the differences in transmissions and gear ratios. Gear ratios in the rear ends and the horsepower ratings of each respective engine. I am just trying to help you find a less costly solution to your problem.You may find changing the rears or transmission may allow you to work in a more comfortable environment and allow you to reduce your fuel costs.

[bryan723]

its the 460 engine with a 13sp mack transmission and 3.7 rear ends I believe.

[rhasler]

its the 460 engine with a 13sp mack transmission and 3.7 rear ends I believe.

The spec sheet for that engine shows the sweet spot at 1650-1750 RPM.

[vision386]

I am also an owner-operator,i run a 2001 CX-613 with a 460,13 spd road ranger,but with 3:90 rears,i consistently average 6.8/7.0 mpg (mind you i do haul lightweight freight) but even when i backhaul a "normal" load 43/44,000 lbs i DO manage 5.5 5.8 sometimes 6.0 but i am also the only person to have driven my truck,and the rear end ratio works out very well for me,paired with 1600/1650 RPM'S i can run in the sweet spot most times,depending on the terrain.....Mark

[bryan723]

The spec sheet for that engine shows the sweet spot at 1650-1750 RPM.

Thanks for the info I will try running in that range, have been running down in the 1300-1400 rpm range (figured lower rpms would mean less fuel??)

[rhasler]

Thanks for the info I will try running in that range, have been running down in the 1300-1400 rpm range (figured lower rpms would mean less fuel??)

Sorry, that information was incorrect, I looked at the sheet for the AI 460. The range for the AC 460P is 1550-1650 RPM. In the 1300-1400 RPM range you are in the peak torque range but only running around 410 HP.

[bryan723]

Sorry, that information was incorrect, I looked at the sheet for the AI 460. The range for the AC 460P is 1550-1650 RPM. In the 1300-1400 RPM range you are in the peak torque range but only running around 410 HP.

Ok will try the 1550-1650 range out. Just seems odd to be running down the road and still have a couple gears that you don't need to use.

[Mackpro]

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.

[cgallamore]

i had 2004 vision with 13 spd and 3.73 gears.

anytime i tried running the lower rpms it would push coolant.

i have an 07 now with 3.96 gears and love it sweet spot between 1500 and 1600.

i had egr cooler problems at the lower rpm also.

jerryb is the most knowledgable when it comes to the 04/05 460 engine.

[bryan723]

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.

What are some of the things you have tried? Would be nice just to be able to put a different engine in there since that would be cheaper then getting a new truck.

[Mackpro]

What are some of the things you have tried? Would be nice just to be able to put a different engine in there since that would be cheaper then getting a new truck.

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.

[rhasler]

I read some information from volvo today claiming that with a properly spec'd wheelbase, which reduces the distance between tractor and trailer (the article claims 40" between the back of cab skin and the front of the trailer is optimum), that an instantaneous gain of 2.5% can be had. The article went on to claim that a full roof fairing can increase fuel economy by 10-15% and side fairings by 2%.

[Mackpro]

I read some information from volvo today claiming that with a properly spec'd wheelbase, which reduces the distance between tractor and trailer (the article claims 40" between the back of cab skin and the front of the trailer is optimum), that an instantaneous gain of 2.5% can be had. The article went on to claim that a full roof fairing can increase fuel economy by 10-15% and side fairings by 2%.

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.

[vision386]

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.

I agree that these upgrades will improve MPG performance,i run full fairings,aero roof,sleeper extensions etc. one noted improvement that i made was to have my exaust manifold ported,and ceramic coated (jet hot coating) seems to help quite a bit,both in power and mpg,not to mention reduced pyrometer temps.....Mark

[QCDriver]

I had 11R 22.5 duals and switched to 455/50 22.5 singles and got an instant increase of .5 mpg. Could help some.

[rhasler]

I looked at the life/trip data from a 2004 CV713 yesterday and it showed to have been getting 6.3 mpg over it's life. The truck has an AI 460, T318LR, and CRD200 series rear ends with 5.02 ratio. I was pretty impressed with that kind of fuel economy. This truck is a body load water truck that sees a lot of off road use. We had a 2011 GU813 demo truck set up for the same application but spec'd with the MP8 505, Allison transmission, and C150 series rear ends with 4.80 ratio that was only hitting around 5.2 mpg

[BGT]

Hi, was looking around last night and came upone this site and thought I would join and see if anyone can help me figure out what to do with my truck. I bought the truck new back in year end of 2004 and previous truck was a 2000 mack vision. Had good success with that truck so figured would trade it for a new one. Well was told the truck should get 6mpg, a little less then what I was getting with the 2000 model, but only way I have gotten close to that is to bobtail. Pulling loads I am 4.5 to 5mpg, depending on weight. So I actually bought a used fld120 with a detroit in it 3 years back and have been driving that and letting the mack sit. I kept the mack because 2yrs left on payments at that point and didn't know how long the freightliner would last, plus I was saving more in fuel then what the two truck payments together were. Anyway the detroit needs an overhaul now so am back to driving the mack. Fuel mileage hasn't gotten any better sitting there. I like look and features of the truck and how quiet it is going down the road but spending $20,000 to $30,000 more in fuel a year doesn't make sense even if the truck is pd for. So has anyone done anything that has improved their mpg? Was seeing some posts about a plate to block the egr sensors and keeping the hot exhaust from going back through the engine again? Or could I just rebuild the detroit and put that into the mack truck so I could get back to the 7-8mpg range? Just trying to figure out some options at this point because being an o/o I need the most efficent truck I can get. I know the cheapest route would be to just rebuild the detroit and put back in the freightliner but that truck is old and noisy and figure since out on the road would be nice to have something quiet to drive and a bit more comfortable. Thanks.

Bryan I have an '05 Vision with the AC 355/380 and 3.90 rears. My last IFTA showed 8.01 mpg over the three month period ending in Dec. The previous showed 7.67 mpg and my worst one last year was the 2nd quarter with 7.27 mpg. All those are 3 month averages. I generally have my cruise set on 59 miles an hour or 1400 on the Tach. When the sensor on my EGR was going bad my mileage dropped into the ranges you are getting with your truck. Mine wasn't throwing any codes only the faint smell of exhaust was noticeable and even then everyone thought I was nuts when I said I could smell it. There was a recall on the exhaust manifold bolts that it seems hadn't been addressed. Those two things alone dropped my mileage down into the mid 5's to low 6's. I was in Phoenix at the time heading back to Memphis. I stopped in at Vanguard and had it checked and after two days of haggling and insisting they finally identified those two issues as being genuine. After replacing the sensor and changing out the manifold bolts my mileage immediately went back to my normal mid to high 7's. So it is possible to get good mileage from these trucks. Anyway just my two cents worth and I highly recommend that you check the recall on those bolts if you haven't already done so as they are what lead to my sensor going out to start with. Best of luck to you!