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Billdozer2 · 05-19-2016, **(Subject: The Mothership needs an MPG Boost )**

(05-19-2016 )Rawze Wrote: I just put my own truck on the road finally yesterday.. First load out .. It was in-framed by myself, and has all brand new pistons, liners, bearings, head, etc. and I counter-bored it too, and it has 3 new injectors. --- SHE BROKE 8.6 MPG ON HER FIRST TRUE FILL-UP going from Georgia, then it headed to North Carolina, and Then to Missouri (second fill-up) with 25K in dry-box that does not roll too good.. Average to location on it is 8.1,.. so IT IS STILL SHOWING II IS UP A BIT!-- New injectors perhaps?

Truck is doing great so far, but it is early to tell. I would have thought that fuel mileage would have dropped way off too,.. but it is not showing it so far. It also has a gallon of Supertech 80/90 gear lube in it.

That's interesting. I would have thought the engine would need to seat before optimum fuel mileage could be attained. I know the whole "breaking in" for car engines is starting to turn into a myth now with better engineering of internal parts (although I still take it easy with a new car cause I'm old fashion like that) but I figured diesel engines would still be designed a little tighter to help make the engine last longer before wearing out.

(05-19-2016 )Rawze Wrote: First of all --- Volvo trucks have a HORRIBLE engine compartment design that is OFF THE TOP --- 0.6 MPG LESS FUEL EFFECIENT THAN ANY OTHER BRAND OF NEWER AERO TRUCK! -- Simply because they have restrictive charge circuits AND horrible design of exhaust flow!.-- PERIOD!--- So you can count on one thing for the whole life of those trucks! --- THEY ARE GOING TO LOOSE FUEL MILEAGE COMPARED TO OTHER AERO TRUCKS IN THAT CLASSIFICATION!. Hell,.. I can fit the turbo and other piping literally inside the piping of even my POS prostar it is so small and restrictive,... YES, they are that bad!. The turbo runs 100 degrees hotter because of poor engine compartment air-flow external to the engine, and that makes the oil run hotter as a result. It is easy to have one running around at 235 F oil temps and it will constantly be in silent derate (lowering its fuel mileage a bit more). The list of problems with Volvo trucks is long, yet everyone seems to love them because they don't look past that interior on them. It is truly a shame. -- The sad part is that everything I mentioned could be fixed by slight design changes to them,.. but I don't think the the Volvo truck company realizes what they have done, or perhaps they are simply too cheap to do things right?.

I think a big problem with the engine compartment is that, granted this is just speculation, the Volvo truck is designed to have the Volvo engine. Granted yes I know you can get a Cummins in a Volvo, but I think that with the smaller size Volvo engine, maybe the air flow would be better? Rawze, what design changes would you do and could something like that be retrofitted onto a current Volvo truck? Just curious and thinking that anything I could do to help my engine/turbo stay cool would be ideal.

(05-18-2016 )brothermothership Wrote: Despite all this, the fuel economy is not acceptable. Most of the time it's 6.0 to 6.3.

What kind of MPGs were you looking to get? Mid 6's seem about right for your truck and the way it is spec-ed out. Maybe after another 25,000 miles, you can get into the upper 6's. But I don't think you are going to get much more than that.

gearhead · 05-19-2016, **(Subject: The Mothership needs an MPG Boost )**

It will get better after about 50,000 in my experance.

Rawze · 05-20-2016, **(Subject: The Mothership needs an MPG Boost )**

I have seen guys cut away at the sides of the fender guards to get better air flow around the engine, and cut away the rubber seal around the radiator on them too. I have also seen them modify the exhaust (after a MM tune) so that they get much better exhaust flow, and that will lower turbo and other temps by about 100 degrees too.

It can be difficult to get a Volvo to run the same cooler temps as say a Pete or KW, or even a Prostar but I have seen it done. As well, if you keep the power restricted on them a bit (power set below about 500 HP) then you don't get as many problems with the smaller restrictive intake and CAC piping so much either. -- these things can help a lot, but in his case,.. they will not help nearly as much as they should because of the high geared rears + Autoshits he has. Any kind of heavy loads and that thing will fight to get out of its own way all the time.

Billdozer2 · 05-20-2016, **(Subject: The Mothership needs an MPG Boost )**

(05-20-2016 )Rawze Wrote: power set below about 500 HP

Guess i should be ok with my 400 HP. Haha. So, i was checking my oil temp while driving along and it sticks around 215 on flat ground and goes up to 225 when climbing. Granted I only run in the northeast. So outside temps don't effect much. What do you think of those numbers?

in2trux · 05-20-2016, **(Subject: The Mothership needs an MPG Boost )**

(05-20-2016 )Billdozer2 Wrote:
(05-20-2016 )Rawze Wrote: power set below about 500 HP

Guess i should be ok with my 400 HP. Haha. So, i was checking my oil temp while driving along and it sticks around 215 on flat ground and goes up to 225 when climbing. Granted I only run in the northeast. So outside temps don't effect much. What do you think of those numbers?

Normal for the N.E. Keeping rpm up around 1600 -1700 keeps the oil temp and pyro down.

brothermothership · 05-28-2016, **(Subject: The Mothership needs an MPG Boost )**

Thanks everyone for your responses, and just so we're clear, I did not spec these trucks....I am just trying to help the office through a bad deal they made. They obviously did not do their due diligence on speccing the trucks for their intended use and terrain, plus the weight of the freight they haul most of the time.
I have been making suggestions and adjustments, looking at the details to make the truck run better.

One update that did help was the progressive shift reprogramming, I picked up about .375 mpg just getting the transmission to shift earlier and faster. The rest of it comes down to engine tuning. Would a higher torque, straight rated engine program ( Cummins has straight 1750 ft/lbs and 1850 ft/lbs programs that would be a great base for some refined tuning that are in the 400 to 485 or so range, I think ) help with masking the transmission and final drive gearing mismatch? My thought is the added torque will help fill in the gap and make the truck more driveable in the mountains and cut the fuel useage in the flat/rolling terrain when driven properly. We can get the dealer to reprogram the ecm since there were a batch of misbuilds that came through and these trucks were part of them.

brothermothership · 05-28-2016, **(Subject: The Mothership needs an MPG Boost )**

(05-19-2016 )Billdozer2 Wrote:
(05-19-2016 )Rawze Wrote: I just put my own truck on the road finally yesterday.. First load out .. It was in-framed by myself, and has all brand new pistons, liners, bearings, head, etc. and I counter-bored it too, and it has 3 new injectors. --- SHE BROKE 8.6 MPG ON HER FIRST TRUE FILL-UP going from Georgia, then it headed to North Carolina, and Then to Missouri (second fill-up) with 25K in dry-box that does not roll too good.. Average to location on it is 8.1,.. so IT IS STILL SHOWING II IS UP A BIT!-- New injectors perhaps?

Truck is doing great so far, but it is early to tell. I would have thought that fuel mileage would have dropped way off too,.. but it is not showing it so far. It also has a gallon of Supertech 80/90 gear lube in it.

That's interesting. I would have thought the engine would need to seat before optimum fuel mileage could be attained. I know the whole "breaking in" for car engines is starting to turn into a myth now with better engineering of internal parts (although I still take it easy with a new car cause I'm old fashion like that) but I figured diesel engines would still be designed a little tighter to help make the engine last longer before wearing out.

(05-19-2016 )Rawze Wrote: You know, if the truck did 6.8 mpg consistently, the owners would be good with that. As it stands, the trailer is probably costing me .5 to 1 mpg. I admit I like the truck despite its flaws, it just should have been specced right.
First of all --- Volvo trucks have a HORRIBLE engine compartment design that is OFF THE TOP --- 0.6 MPG LESS FUEL EFFECIENT THAN ANY OTHER BRAND OF NEWER AERO TRUCK! -- Simply because they have restrictive charge circuits AND horrible design of exhaust flow!.-- PERIOD!--- So you can count on one thing for the whole life of those trucks! --- THEY ARE GOING TO LOOSE FUEL MILEAGE COMPARED TO OTHER AERO TRUCKS IN THAT CLASSIFICATION!. Hell,.. I can fit the turbo and other piping literally inside the piping of even my POS prostar it is so small and restrictive,... YES, they are that bad!. The turbo runs 100 degrees hotter because of poor engine compartment air-flow external to the engine, and that makes the oil run hotter as a result. It is easy to have one running around at 235 F oil temps and it will constantly be in silent derate (lowering its fuel mileage a bit more). The list of problems with Volvo trucks is long, yet everyone seems to love them because they don't look past that interior on them. It is truly a shame. -- The sad part is that everything I mentioned could be fixed by slight design changes to them,.. but I don't think the the Volvo truck company realizes what they have done, or perhaps they are simply too cheap to do things right?.

I think a big problem with the engine compartment is that, granted this is just speculation, the Volvo truck is designed to have the Volvo engine. Granted yes I know you can get a Cummins in a Volvo, but I think that with the smaller size Volvo engine, maybe the air flow would be better? Rawze, what design changes would you do and could something like that be retrofitted onto a current Volvo truck? Just curious and thinking that anything I could do to help my engine/turbo stay cool would be ideal.

(05-18-2016 )brothermothership Wrote: Despite all this, the fuel economy is not acceptable. Most of the time it's 6.0 to 6.3.

What kind of MPGs were you looking to get? Mid 6's seem about right for your truck and the way it is spec-ed out. Maybe after another 25,000 miles, you can get into the upper 6's. But I don't think you are going to get much more than that.

brothermothership · 05-29-2016, **(Subject: The Mothership needs an MPG Boost )**

I didn't know if the response for mpg was seen, if the truck can get to 6.8 the office would be good with that. As I said before, the trailer is part of the problem. It is definitely out of alignment.

Rawze · 05-29-2016, **(Subject: The Mothership needs an MPG Boost )**

(05-29-2016 )brothermothership Wrote: I didn't know if the response for mpg was seen, if the truck can get to 6.8 the office would be good with that. As I said before, the trailer is part of the problem. It is definitely out of alignment.

Its called custom tuning and driving it right.