GMC Duramax vs Ford Powerstroke? - Page 2 - Montana Owners Club

richfaa · 07-08-2010, 03:34 AM

Dave. I have used Diesel kleen Cetane boost in every tank of fuel since day one. We were on the Ohio/, Ind tpk yesterday. Was doing our usual 10/10.4 mpg pulling the 3400.Stopped for fuel at a Valero station on the TPk and took on 28 Gallons of diesel. It was so &%$## hot that we did not add the additive. We got no better than 8.2 mpg for the rest of the trip. What a difference. Additive goes in before we leavew this AM...

TAKPAK · 07-08-2010, 04:35 AM

Everybody has certainly weighed in on this subject. Regarding fuel filter changes, I do our Duramax about every 15,000 to 20,000 or so. I don't get too worried, as I have my own fueling station/tanks at home, so I have a really good filtering system. That said, you can't fuel from home if you are on the road, unless you have a "transfer tank" on board. I do not add anything to the fuel. Empty, on the highway I get 20 plus MPG, at 65 MPH. Pulling the 3400 I get at least 11 MPG, and sometimes as high as 13 MPG. I hold my speed at about 62 MPH. That keeps the RPM right in the 1600-1800 range, which is the peak torque for the engine.IF I am on flat ground, freeway or such, I also take it OUT of tow/haul mode and just let it cruise. If I hit heavy traffic, or hills/mountains, then back to the tow/haul mode it goes. I was always a Ford fan, but I sure like the Chevy/GMC/Duramax/Allison combination. Just my ".75" cents worth (2 cents devalued due to economy)!

mlh · 07-08-2010, 05:14 AM

Montana Sky
8e3k0 did the same thing I did take the DPF off and install a Spartan tuner, it's that easy. If you do that you will have a different truck. If you buy a new Duramax you will have the same problems you have now. The problem is not in the trucks its in the pollution controls. The lag your truck has pevents soot from being formed. The turbo makes boost then it adds fuel. That equals turbo lag. Bottom line if you wont a truck to run like your old Dmax and get the same fuel mileage, you need to get an old Dmax or get the DPF off of your truck.
My brother and I have pulled my Monty with both his 06 Max and my 08 6.4. even he, a die hard Chevy fan says there is no difference in way the 2 trucks pull the camper, when the 2 trucks are stock. Now that I have an extra 210 HP there a huge difference.
Lynwood

TLightning · 07-08-2010, 07:40 AM

Quote:

quote:Originally posted by mlh

Montana Sky
8e3k0 did the same thing I did take the DPF off and install a Spartan tuner, it's that easy. If you do that you will have a different truck. If you buy a new Duramax you will have the same problems you have now. The problem is not in the trucks its in the pollution controls. The lag your truck has pevents soot from being formed. The turbo makes boost then it adds fuel. That equals turbo lag. Bottom line if you wont a truck to run like your old Dmax and get the same fuel mileage, you need to get an old Dmax or get the DPF off of your truck.
My brother and I have pulled my Monty with both his 06 Max and my 08 6.4. even he, a die hard Chevy fan says there is no difference in way the 2 trucks pull the camper, when the 2 trucks are stock. Now that I have an extra 210 HP there a huge difference.
Lynwood

Your truck, your money, your decision, but my owner's manual very clearly states that ANY mod put on the truck may void the warranty. That's a gamble I'm not willing to take.

SlickWillie · 07-08-2010, 10:57 AM

Anybody know what the original topic was? Let's see, the OP was looking to minimize maintenance expense due to misinformation about filter maintenance schedule. I don't think he reported a lack of power from the Duramax.

When Ford resolves the issue of cab off major engine repair, I might be driving one. Oh, in fact, I would have probably been driving one right now if not for that.

skypilot · 07-08-2010, 12:25 PM

Will: That 'cab-off' requirement has been lifted on the new 2011's (at least according to the web site and information on the new one). The rest of the maintenance -- filters, oil changes, etc., -- remain the same as days of old.... I had the opportunity to drive a 2011 F250 -- what a dream -- quiet and powerful -- and dang expensive -- had the King Ranch option with everything except the kitchen sink... That said, fuel filters on the D-Max should be 15K or so.........

Montana Sky · 07-08-2010, 05:06 PM

Rich, I run Ford's diesel fuel conditioner and have not found it to help increase fuel economy. I'll have to try Powerservice to see if that makes a difference. I have always changed my fuel filters at 10K on my Dmax and have continued that practice on the Pstroke. Removal of the DPF system is not an option for me as I bought the 100K bumper to bumper warranty when I bought the truck.

richfaa · 07-09-2010, 04:22 AM

We let then fuel run down.Took on 29 gallons of Amoco and added the proper amount of additive. The MPG went back to 10.2 mpg average. I think it was a combination of crappy Valero fuel (Valero is off my list) and not adding the additive. The is no doubt in my mind that the DURIMAX( the newer ones) does better MPG solo but our observation from folks we run with and pull comparable weights
with compairable trucks the MPG towing is nearly the same...10/11 mpg. Ther cummins does even better both towing and not towing but still on the newer ones it is not that much different. Had the Dodge made a long bed CC in 08 we wouold have one of those. I have driven a lot of cummins diesels. This 08 f-350 has more power than we can use and I would like to see better MPG but 10/10.5 I feel is not bad.

SlickWillie · 07-09-2010, 05:31 AM

Quote:

quote:Originally posted by skypilot

Will: That 'cab-off' requirement has been lifted on the new 2011's (at least according to the web site and information on the new one). The rest of the maintenance -- filters, oil changes, etc., -- remain the same as days of old.... I had the opportunity to drive a 2011 F250 -- what a dream -- quiet and powerful -- and dang expensive -- had the King Ranch option with everything except the kitchen sink... That said, fuel filters on the D-Max should be 15K or so.........

Cab removal PDF Looks like they made some progress. Still not sure. Suppose time will tell.

CamillaMichael · 07-09-2010, 07:27 AM

Quote:

quote:Originally posted by TLightning

The pot will really be stirred when Honda and Toyota come up with diesel duallys!

Not only will they expand the market, but the Toyotas would make parts purchases unnecessary since you could follow a Toyota down the road and pick up whatever you happen to need as they drop off the vehicle in front of you...just kidding (sort of). Given what I have seen of their "big rigs" in Japan, I do not think the Japanese will come up with anything anytime soon to tow our Montanas. But if they do, they have some pretty serious competition with the American made trucks.

skypilot · 07-09-2010, 12:28 PM

Regarding the Cab-off change -- I was talking about the 2011s with the new engine. With the move to the turbo in the engine valley (up top) they say that all that maintenance can now be done from the top end -- at least according to one of the magazine (ezine) articles I've read on the new Ford Super Dutys. Regardless, as you said, they have got to do something about it -- removing the body to work on the engine can not be good for the customers wallet!!!!

sreigle · 07-09-2010, 12:57 PM

Question - on the new GM and Fords that require the diesel exhaust fluid, don't they also have the DPF diesel particulate filter? I heard they have both. Is that wrong?

mlh · 07-09-2010, 03:01 PM

Steve
You are wright they do require both.
Lynwood

Montana Sky · 07-09-2010, 06:47 PM

Steve, only the current Dodge diesel does not require the exhaust fluid. Both Ford and GM are using the fluid. GM is claiming the new 2011 Duramax averages 19 MPG highway.

SlickWillie · 07-10-2010, 04:42 PM

Well, I know we're getting way off topic, but what the heck. Our 09 Duramax will average 19 highway. But, I am real concerned about towing mpg. We had to pull out when Alex threatened (high water), and I saw about 7 mpg towing. Now, I only towed about 30 miles total, but I am concerned, as the 04 GMC Duramax averaged 9-12 mpg.

camper4 · 07-11-2010, 03:50 AM

I think some of the confusion about 'improved mileage' goes back to late 2007 when they first put the filters on the exhausts. When they did that they decreased mileage slightly as they used extra diesel fuel to help regenerate the filter. Now they use the new fluid to do that so the mileage increases back to what it used to be in early 2007, before the filters.

Also the late 2007 filters increased back pressure before they regenerated. The new 2011 trucks use the urea fluid to regenerate more often to help keep back pressure lower.

richfaa · 07-11-2010, 04:01 AM

The 2011 year trucks still have the DPf and still regenerate.

You may also like: