Engines and MPG
 

I'm wondering just what engine gets the best fuel economy? :confused:

Currently I have a 2005 Volvo with the Volvo 12 for an engine. Getting very low fuel mileage like under 6 mpg. :thumbsdown: I am seriously thinking of trading off mid year. I have driven Freightliners with Detroits and have gotten mid 6's for mpg. My main loads are paper and are in the 40,000 plus range in the mid to eastern part of the county.

I am interested in what others are getting with Cummins which is the other engine offered by Volvo along with a few other truck manufactures. Any good advice?

There's absolutely no way to tell unless you get 10 of each engine make on an engine dyno, and they're all scientifically studied. I've heard of some folks getting great mpg out of newer Volvo's. I know one guy pulling off low 6's with his 535 hp D16. That's very good for what he's doing, and a full MPG better than the 05 ISX he had before. Almost exact same truck, and the loads are the same.

What we do know is EGR hurt us bad, and DPF's hurt us more.

It comes down to specs, drivers habit (mostly speed), maintenance, and there's always that wildcard "random" factor.

3406B Cat......... 5.5 to 6.5 depending on the driver (me), load, winds, etc.
Best thing about it..... no computers, no EGR, no DPF.

I ran into one guy who bought one of the new Volvo's with a Cummins and he was only getting around 4.5 mpg. I have spoken to others who have told me they were getting great mileage with their Volvo engine. Although CAT has a reputation for getting poor fuel mileage, I have always gotten good fuel economy with my CAT's. I average over 6 mpg with both of them. If I were to buy a Volvo I would want a Cummins. Most people whom I know who own a Cummins do pretty well with fuel mileage. Another factor is that it should cost less to make repairs on the Cummins. I also like the idea of being able to go to most any garage and have repairs made. Any time you have a brand specific engine, such as Volvo, you are more likely to need to go back to a dealer for any repairs. Their labor rates are normally higher and parts which are proprietary are always going to cost more.

I agree with you on the fact that it is easier to get repairs on Cummins than having to rely on finding a Volvo dealer. I have had to make major repairs to the tune of $7,000 on this truck since buying it in June '09. I am trying to do all the things I can do as a driver to increase mpg. Had the charged air cooler check since I had a condensation leak (water leaking out of bottom hose). They found no problem with cooler and no leaks until they reset the lower pipe and ended up with an air leak. Had another shop reset the pipe and they added some silicone on the O ring and after that my fuel mileage came up to 6 and sometimes a bit better to 6.2. The engine was put on a dyno and it was found within paramater?

Doesn't sound like any engine is getting better than 6 or so. I had an '07 Freightliner Columbia with a Detroit when I was a company driver and got 6.3 with idling (no APU). I have an APU on this Volvo.

Just was interested in what drivers are getting with the Cummins. I hate to take a salesman's word (about as good as a dispatchers word). I will stay with this truck if trading into a truck with an Cummins isn't going to improve my fuel mileage.

A friend of mine has a N14. He gets around 7 mpg pulling his flat bed and in the low 6's pulling his van. I know they don't make the N14 any longer, but he usually does pretty well on his Cummins. He just had it overhauled last year. I am not sure how well any of these new engines are doing. I think for the most part Detroit and Cummins have done a little better than CAT, but the driver has as much or more to do with fuel mileage than the engine. I have seen that in my own trucks. I notice that I will usually get better fuel mileage than when I have a driver in the same truck. I am not sure that there is much difference in fuel mileage with any of the new engines.

40,000 lbs is a lot of weight. You probably don't have enough torque in the 12L engine and it works too hard to move that load up North East hills. I have a CAT C15 and my fuel mileage with heavy loads improved when I changed my torque rating from 1650 to 1850 and then did ECM performance tuning at the local CAT dealer. I'm from Ontario Canada and spend most of the time in North East USA.

My company just put me in a brand new Mack Pinnacle with the Red MP8 motor. I currently have 2400 miles on it, it's rated for 338 HP at 2000 rpm's, and gets around 5.6 mpg. I run a dedicated trash run 90 miles one way, loaded going west, empty going back east. I was suprised it's not a little better, we run full fairings including the roof, but I have to factor in when going back east I have a 53 open top trailer that's fighting me with quite a bit of wind resistance.

when I was at the dealer looking at new Kenworths, a guy came in with a W9 that had a cummins isx, he had 2500 miles on it and there were 240 faults codes in it, he was NOT a happy camper
when I left he was demanding a new truck, I dont know what ever happened

I have never heard of anyone having that many fault codes. In fact, I didn't think there were 240 different fault codes. I think if I were him I would want a new truck, too. It is probably something simple like a sensor or loose wire. :confused:

A lot of times the same code will keep recurring.

i for one am not a fan of the volvo motors. i used to run a day cab with the vd12 or whatever they call it in a 04 volvo. the worst motor i ever drove. foot always in it. then again i think there was issues with it. on flat ground it would just slow down for no reason.

anyway, i'm a die hard cummins fan. when i was looking for trucks a few months back i wanted a isx. i called up and talked to some people. they said that they'll get well in to the 7's. (old fleet trucks). maybe this is true.. but what is the speed limited to? my company truck now is a day cab columbia with a s60. its limited to 65, i 90& of the time get anywhere from 7-7.5. before it was turned down it would run about 74. i would get anywhere between 6.75-7.1. we do run light though. anyway. my truck went down a few weeks back and i got a columbia with a c15.. it got just over 5. but there has to be a way to pull mpg out of them.. i'm noticing a lot of fleets are running c15's now. guess its all in how you drive and the load.

It is so hard to compare engines because there are so many ways to set up a truck and so many applications a truck can be used in. Also, studies have been shown that there is at least a 20% difference in fuel economy between the best and worse drivers under identical situations. Cummins covers the topic of fuel economy quite well in the PDF document at the following address:

http://www.everytime.cummins.com/ass...Whitepaper.pdf

While I’ve never owned one, Detroit has always had a good reputation when it comes to fuel economy (one of the primary reasons a lot of big companies run them) and they are easy to find service for out on the road. My 2003 CAT C-15 had a lifetime average (in the 645k miles that I put on it) of 6.2 mpg. My 2006 ISX was averaging 6.7 mpg before I unplugged my EGR, and since has gone up to 7.2 mpg in mostly winter driving, which always hurts economy.

Finally, keep in mind when talking to people about their own fuel economy that there are several ways to derive their economy numbers. Some will simply look at their ECM report or go by what their computerized in-dash display tells them. Both of these methods will yield inaccurate data. The only way to accurately figure and track fuel economy is by the “at the pump” numbers. Take the miles you have driven since your last fill-up and divide by the gallons required to fill your tank(s) back up. I do this with every fuel purchase from the first day I buy a truck and keep the data forever in an Excel spreadsheet so I can analyze trends that might take many tens of thousands of miles to develop.

was thinking about upgrading my old Volvo (1999) with Cummins N14 for a Freightliner with Cummins ISX on which EGR will be turned off immedeately (Thanks to your posts of cause! ) . Right now I got 6.7-7.0 depending on speed. Usually when I'm doing my IFTA it around 6.8

When I was driving my 2001 Mack with 460 hp Mack E-7 engine, it would take considerable effort on my part to get below 6.6 mpg. Many times I was up around 7. Then I was in a 2009 Pete with 550 hp Cummins ISX and it stayed at 4.5 mpg no matter what.

My bullhauling partner drove an old Freighliner FLD with a 525 hp Detroit and he usually got around 6 mpg.

You asked for advice: I say stay away from new engines if you're looking for fuel economy.

and you can't hardly trace down the problems when you have wiring problems. :confused:

1998 T800 11L M11 Cummins 370/410 13 spd OD 4.33 rear = 6.0 mpUSg winter at 60 - 65 mph in NY state

2008 T660 14L ISX Cummins 485/485 13 spd OD 3.9 rear = 5.0 mpUSg winter at 60 - 65 mph in NY state

the more I read about newer trucks the more I want to keep my ole one. at 60-65 mp.h I'll ave 6.25-6.75 m.p.g. not to mention the parts for my 11.1 ser 60 det are dirt cheap compared to newer ones. I talked to 1 of our drivers yesterday, have not seen him in a week. said he was having injectors put in. $ 4000,00 from thompson cat. I told him I had my put in by a local dealer last year. dropped truck off at 3 p.m. & picked up truck at 10:30 pm that same night. 2,400 for everything. including a new e.c.m wiring harness.

he said yeah but I got the yellow motor. he get's 5 m.p.g. if lucky. I got a price on a turbo for my truck. $650.00 not bad considering what I hear the rates for newer trucks. I am not knocking cat or what anyone has. the new det's are a lot more money for their parts than mine are too. turbo still original 1.3 mi miles.

I hate new trucks.

This '08 T660 is the same darn truck as our '95 T600 and '98 T800. Matter if fact lots of stuff isn't as good.....like whose idea was it to switch from toggle switches to rockers? And those aero dynamic mirrors still vibrate like they did 13 years ago. And you still have to make a choice between warm feet and a clear windshield because you can't have both. And don't get me started on DPF's and EGR and bad/unproven designs like EGR coolers going bad and a new starter every year and a new turbo in the first year.

But they are more quiet.

I like noise & a rough ride.. it keeps me awake. lol. $15,000 over 11 years ago for my truck & I am still driving it. that is why I like what I have.

We currently have plates on a '98 T800, '01 T2000, '05 T2000, '08T660. The '98 is the tightest truck of them all.

How much have you spent on maintenance?

I only have 1 truck. how much I spent on maint? since I bought truck? yearly? I dont have the numbers in front of me. have not spent much at all over 11 years. most of mine were preventative maint fix's. my clutch went 1.1 mil before being replaced. bottom 1/2 done at just over 1 mil, preventative there. cost 900.00 6 injectors at over 1.2 mil. thats all the major I had ever had done. the rest was, the normal wear & tear stuff.



after accumulating the assets that I have, since I bought my truck, from my earnings from that truck. I know I have done well. good business sense, luck? both? whatever. I have done well, with one truck. I have had no where near the problems that I hear others drivers have with newer truck, & I never had a truck payment. I will be doing my taxes soon & will have a breakdown on my expenses.

yep I was wondering how much you spent in total over the 11 years.

You know, that's why I'm pretty determined to stick with my old truck at this point. Most of the guys I've talked to with newer trucks aren't too crazy about them. I would like to see better fuel milage out of it, and I think I can get it with a rebuild, when it's ready for one. The thing that concerns me is if the emission standards increase and I'm forced to retrofit the old motor, then I would have to buy something newer, I guess.

I'm also just on the cusp of taking this philosophy to my personal vehicle. I might keep my newest one but sell the other two and get older pick ups with no computers, something I can work on again. I've been keeping my eye out here and there.

oh GOD.. I don't think I want to go into the attic & drag down all the boxes of previous years records. I can tell you this. I never had a major breakdown. never had to have a service truck come out anywhere other than to have a tire repaired in over 11 years. I never spent more on maint in any year, than if I had your average truck payment.

Now you got maint & repairs. most all of mine was, what anyone would put into any truck. oil change's, batteries, wheel seal's e.t.c. I mean everything is a wear & tear item on a truck & has to be replaced at some point in time. I will say I think my truck has been one of the best. having the original clutch go over 1.1 mi miles.1 alternator, 1 water pump, one u joint, since I had truck. most of my trucks components are original. some work I had done, as preventative, not caus it was showing wear. still original turbo, I did have the air comp, replaced a few years ago. again preventative there. wish I had not done that. my original, that I thought must be wore, did better than the replacement. live & learn. A lot of work I have done myself & learned so much more than if I had nothing to work on. as most of us did back in the day working on our ole beater of a car.

I think the main thing, is if the Truck is right for you. :thumbsup:

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