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

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.