Ecoboost question for DP

[dodge man]

Pretty sure they do regen with diesel fuel.

 

[TheGoose]

My understanding is that while they still use diesel fuel to regen the DEF lowers the temperature required for the regen and thus lowers the amount of diesel fuel being injected.

 

[xring100]

What winter tires are you using? We have two Cruze TD's, we have Altimax Arctics and Nokians and the difference is pretty small.

How do you like your diesels?

I run Michelin x-ice 3 supposedly green x lower rollong resistance.
In normal rural off highway driving 55 mph i only see about a 4-5mpg shift. 70mph is definitely 7-9 mpg though. Im sure that remote starting in the cold doesn't help her tank averages.

A guy at work put 18" Verano take off wheels and an all season tire on his diesel cruze the day after he bought it. He couldn't figure out why he was getting only 35 mpg even after 3000 miles. he brought it into the gm proving grounds where they did a fair amount of testing looking for issues finally they decided to do an A-B-A-B test on the 18" goodyear eagle ls and the stock good year. They drove 70 mph around the circle track. Which is 4.7 miles they reset the odo once up to speed and made several laps. What they found was the eco tires got between 5.5 -6 mpg different at 70 mph they got nearly identical results both times.
I had Michelin harmony tires on my saturn but i ran Bridgestone blizzaks WS60's on the car in the winter i didn't install them until needed such that i would wait until after the switch to winter blend and i would go from 38 mpg down to 34mpg after the switch this was my normal rural 55mph commute. The harmony tires were not a low roller either so it. I saw similar % reduction on the grandprix going from good year assurance tripple treads to blizzak ws70's.
In both cases these were shifts from standard all seasons to snow tires.
Thus it stands to reason that one can expect a fairly large change going from an ultra low rolling resistance tire to a snow tire.

 

[aczlan]

I am curious, was the inflated diameter the same between summer and winter tires?
I see a noticeable difference in mpg on my car (2-3 mpg less in the winter) and have noticed that the inflated diameter is different by 0.5" and my speedometer goes from being right on to reading 2-3MPH faster than my ground speed (per the GPS on my phone).

Aaron Z

 

[fordmantpw]

Lots of misinformation here about regens.

First, yes, the new diesels do still regen, and yes the DO use diesel fuel to regen. DEF is not flammable and won't burn to heat up the DPF to burn off the soot. DEF is (I think) 67% water, the rest is a mixture with a lot of ammonia in it.
Second, DEF is used to lower NOx emissions in order to meet emissions regulations. All trucks with DEF us a special DEF injector to inject DEF into the exhaust to mix with the NOx. The chemical reaction breaks down causes the NOx to combine with the NH4 in the DEF to produce water vapor.
Thirdly, DEF itself does not affect regens and in no way is it tied to regens. However, the use of DEF to reduce NOx allows the trucks to run less EGR, thereby running a bit higher combustion temperature, resulting in less soot buildup in the DPF, which in turn requires less regens. More infrequent regens leads to better fuel economy. Make sense?

They may not be 100% correct, but it is a lot closer than some of the other posts.

Also, GM puts a 9th injector in the exhaust (in the DPF maybe) for the Duramax to inject fuel into the DPF whereas Ford uses an extra injection in the exhaust stroke to get fuel into the DPF. I'm not sure how the RAM Cummins works or Fiat EcoDiesel work.

 

[xring100]

I am curious, was the inflated diameter the same between summer and winter tires?
I see a noticeable difference in mpg on my car (2-3 mpg less in the winter) and have noticed that the inflated diameter is different by 0.5" and my speedometer goes from being right on to reading 2-3MPH faster than my ground speed (per the GPS on my phone).

Aaron Z

Good question I'll have to put my gps in it with the snows to check the speedo.
I know the Static loaded radius was nearly identical only a couple mm difference. the two tires that showed the 5.5-6 mpg difference.

What kind of car and what is the mileage do you normally get.

This was round trip to rose city drove 65 mph on the highway because my buddies trailer was causing his truck to shudder so bad we stopped to check the trailer bearings. Had several trips into town.

At 65 mph my saturn would touch 40 mpg at 65 mph the cruze is in the mid 60's mpg

DIC actually reads low in reality car does between 0.3 mpg better in summer temps or 1.5 better in winter with remote start. The energy engineer says it has to do with remote starting and computer improperly report consumption




With some stop and go around saginasty i mean saginaw. Due to road destruction or whatever MDOT does in Michigan when its not winter.


Same trip

 

[aczlan]

Good question I'll have to put my gps in it with the snows to check the speedo.
I know the Static loaded radius was nearly identical only a couple mm difference. the two tires that showed the 5.5-6 mpg difference.
What kind of car and what is the mileage do you normally get.

I have a '97 Volvo V90 (RWD wagon with a straight 6). I get 18-19MPG in the winter and 19-21MPG in the summer (depending on how much I play with the skinny pedal).

Aaron Z

 

[BrinkME]

I know this is getting off-topic, but it seems people are confusing DPF's (Diesel Particulate Filter . . . this is what needs to 'regen, i.e. burn out the soot), SCR's (Selective Catalytic Reduction), and DEF (Diesel Exhaust Fluid . . . this is injected into the exhaust stream before the SCR and reacts to reduce NOx)

 

[Garandman]

.

 

[wawajake]

you can easily see it is a downhill situation..........heck have had to do that with a 1993 Jeep Cherokee 6 cylinder and was successful.......but it was downhill like this is...........probably empty trailer so not enough weight on his drive axles.