Fuel mileage - 1st tankful

Goglio704 · **Posted:** Thu Jul 27, 2006 6:54 pm

I'd verify the speedometer and odometer against a GPS unit first. My speedometer is pretty much on, but the odometer is 2% low. Sounds like your mileage is off by more than 2%, but verifying the guages is a good place to start. Are you running stock size tires?

sempe02 · **Joined:** Sat Jul 08, 2006 10:35 pm **Posts:** 20

yes the tires are stock and i have checked it with radar and the speedo is on wouldnt that mean that the odometer is right

Goglio704 · **Posted:** Thu Jul 27, 2006 7:06 pm

On mine the speedo was right, but the odo was still off by 2%. Still, I doubt there is enough discrepancy between the two to account for your low mileage. Mine is lower than what some are getting. 22 in town, maybe 25 on the highway. I'm at 8000 miles now, and it seems to get a little better every time I check it. When you say all city, are you talking about stopping at every light and waiting through one or more light cycles before you get through an intersection? Your mileage might be about right for that kind of drive.

sempe02 · **Joined:** Sat Jul 08, 2006 10:35 pm **Posts:** 20

through a subdivison and some lights but its not stop and go

Goglio704 · **Posted:** Thu Jul 27, 2006 7:35 pm

Sounds like something's not right. You could check to make sure the EGR flow control valve is not stuck partially closed.

vtdog · **Joined:** Fri Sep 30, 2005 11:27 am **Posts:** 640

That's about the lowest mpg (except for consumer reports) I have ever seen listed on this site. You should demand that dealer check it out.

BLake · **Posted:** Thu Jul 27, 2006 8:22 pm

Last tank, 16.5 MPG. 3/4 highway (60mph), 1/4 city. I was driving in such a way as to get good milage. Milage has been dropping 1mpg per tank over the last 3 fillups. I have 5500 miles on it now. I'm taking mine to the dealer this week.

My speedpmeter is off by 3 mph at all speeds vs GPS, haven't checked the odometer yet. Something is NOT right with this car.

Cowcatcher · **Posted:** Thu Jul 27, 2006 8:33 pm

I just drove cross state into a strong wind then south for a total of around 500 miles. Before I hit bad traffic today I was up to 28.5 but I have a 6% odometr error that when factored in pushes it up tp 30.2. A little over 12K on an '06.

Marlon_JBT · **Posted:** Thu Jul 27, 2006 8:34 pm

My '06 has 1800 miles on it now and my EVIC tells me (city and highway driving) that I'm averaging about 18.3-19.0MPG.

Not pleased, but slightly better than my 3.7L. (16MPG...17MPG if I tried hard enough.)

I'm going to hand calculate this tank...

DarbyWalters · **Posted:** Thu Jul 27, 2006 8:36 pm

Any consistent mileage under 17 means something is wrong I would think...

I would pull off the CAC tube to see if it has oily sludge...then the intake and check it.

Bovie · **Posted:** Thu Jul 27, 2006 11:33 pm

My first tank was 20.49mpg what was amazing (To me at least) was that the computer was spot on with a 20.3 somthing. My bosses Dodge Ram with the cummins is almost always 2-4mpg off of what he really gets.

My 2cd tanks looks like it is going to be another 20.5 or 21 mpg. 70% of my driving is 50mph so I hope this impoves a little bit over time.

oldnavy · **Posted:** Fri Jul 28, 2006 6:57 am

Bovie wrote:

My first tank was 20.49mpg what was amazing (To me at least) was that the computer was spot on with a 20.3 somthing. My bosses Dodge Ram with the cummins is almost always 2-4mpg off of what he really gets.

My 2cd tanks looks like it is going to be another 20.5 or 21 mpg. 70% of my driving is 50mph so I hope this impoves a little bit over time.

At 50 mph you are not driving fast enough to get TQ lock-up and will get less fuel mileage. The TQ needs to hit 58-60 mph before that happens, which will drop rpm's and increase fuel mileage. At 65 to 70 mph you should be hitting 30 mpg range and once broken in that range should net you mid 30's without much problem as it does others here. You have to learn to drive the proper torque/speed range and when you do the ecomony will be oh so sweet. :wink:

bigcanoe · **Joined:** Mon Oct 31, 2005 5:33 pm **Posts:** 96

My first tank on my used CRD:

21.2 MPG, all town driving, never over 45mph, running the AC almost all the time...is that normal? It seems ok to me.

DarbyWalters · **Posted:** Fri Jul 28, 2006 11:14 am

That is good for real stop n go traffic...

bigcanoe · **Joined:** Mon Oct 31, 2005 5:33 pm **Posts:** 96

Me too, and I love my CRD so far

Marlon_JBT · **Posted:** Fri Jul 28, 2006 5:31 pm

I finally saw something over 19MPG today.... 19.2! :lol:

I filled up yesterday ($42... ouch!)

I have driven a total of 50 miles today Mostly suburban city, and about 4 miles highway. EVIC tells me I'm getting 19.2MPG. This tank is an experiment...

A/C on or off, doesn't matter, doesn't make mileage worse.
Under 2000rpm actually hurts my mileage. 22-2400RPM seems to be the perfect range.

Waiting to see 20MPG...

Reggie · **Posted:** Fri Jul 28, 2006 5:49 pm

oldnavy wrote:

At 50 mph you are not driving fast enough to get TQ lock-up and will get less fuel mileage. The TQ needs to hit 58-60 mph before that happens, which will drop rpm's and increase fuel mileage. At 65 to 70 mph you should be hitting 30 mpg range and once broken in that range should net you mid 30's without much problem as it does others here. You have to learn to drive the proper torque/speed range and when you do the ecomony will be oh so sweet. :wink:

While ON's rig may indeed be able to get to the magical 30mpg number, for a lot of us it seems the ONLY way to get 30MPG will be on the back of a tow truck. I just finished a 700 mile all highway trip and although I did get better than my usual 20.5 mpg, my actual mileage for the trip was 25.9 mpg. Speed was 65 - 67 mph most of the way dropping to 60 mph in some areas, my tires were at 36 - 37 psi cold, new air filter, just changed rear axel fluid as well as xfer case fluid. The diesel down here in the Houston area has to conform to TX-LED so it has a minimum cetane of 48. The last batch I tested was 53, but there is no telling what the fuel quality was in Denton where I topped off at. My rig has over 13k on the odometer so I don't expect any big increase from continued break in. I think the only way I can get near 30 mpg will be to change the muffler and/or exhaust, fill up with VW 506.01 oil, and find a way to play with the injection timing. Also driving on flat surfaces on a cool day with no AC on and no wind will also help. Good luck in your quest.

oldnavy · **Posted:** Fri Jul 28, 2006 6:38 pm

Reggie wrote:

oldnavy wrote:

At 50 mph you are not driving fast enough to get TQ lock-up and will get less fuel mileage. The TQ needs to hit 58-60 mph before that happens, which will drop rpm's and increase fuel mileage. At 65 to 70 mph you should be hitting 30 mpg range and once broken in that range should net you mid 30's without much problem as it does others here. You have to learn to drive the proper torque/speed range and when you do the ecomony will be oh so sweet. :wink:

While ON's rig may indeed be able to get to the magical 30mpg number, for a lot of us it seems the ONLY way to get 30MPG will be on the back of a tow truck. I just finished a 700 mile all highway trip and although I did get better than my usual 20.5 mpg, my actual mileage for the trip was 25.9 mpg. Speed was 65 - 67 mph most of the way dropping to 60 mph in some areas, my tires were at 36 - 37 psi cold, new air filter, just changed rear axel fluid as well as xfer case fluid. The diesel down here in the Houston area has to conform to TX-LED so it has a minimum cetane of 48. The last batch I tested was 53, but there is no telling what the fuel quality was in Denton where I topped off at. My rig has over 13k on the odometer so I don't expect any big increase from continued break in. I think the only way I can get near 30 mpg will be to change the muffler and/or exhaust, fill up with VW 506.01 oil, and find a way to play with the injection timing. Also driving on flat surfaces on a cool day with no AC on and no wind will also help. Good luck in your quest.

I still bet you guys with only 20 mpg hwy mpg's have a fuel pressure problem, and techs that don't know how to figure out why.

Reggie · **Posted:** Fri Jul 28, 2006 6:46 pm

oldnavy wrote:

Reggie wrote:

oldnavy wrote:

At 50 mph you are not driving fast enough to get TQ lock-up and will get less fuel mileage. The TQ needs to hit 58-60 mph before that happens, which will drop rpm's and increase fuel mileage. At 65 to 70 mph you should be hitting 30 mpg range and once broken in that range should net you mid 30's without much problem as it does others here. You have to learn to drive the proper torque/speed range and when you do the ecomony will be oh so sweet. :wink:

While ON's rig may indeed be able to get to the magical 30mpg number, for a lot of us it seems the ONLY way to get 30MPG will be on the back of a tow truck. I just finished a 700 mile all highway trip and although I did get better than my usual 20.5 mpg, my actual mileage for the trip was 25.9 mpg. Speed was 65 - 67 mph most of the way dropping to 60 mph in some areas, my tires were at 36 - 37 psi cold, new air filter, just changed rear axel fluid as well as xfer case fluid. The diesel down here in the Houston area has to conform to TX-LED so it has a minimum cetane of 48. The last batch I tested was 53, but there is no telling what the fuel quality was in Denton where I topped off at. My rig has over 13k on the odometer so I don't expect any big increase from continued break in. I think the only way I can get near 30 mpg will be to change the muffler and/or exhaust, fill up with VW 506.01 oil, and find a way to play with the injection timing. Also driving on flat surfaces on a cool day with no AC on and no wind will also help. Good luck in your quest.

I still bet you guys with only 20 mpg hwy mpg's have a fuel pressure problem, and techs that don't know how to figure out why.

I could well be related to fuel pressure but if I was to hazard a guess it could be that those of us with low fuel economy have our operating specs on the low end of what ever has an adverse impact on fuel economy. It might be that our fuel pressure, valve timing, and crank position signal are ALL on the low end, but still in the operating window. Because everything is within spec the dealer won't fix it. Actually it would be next to impossible for the delaer to get STAR to authorize the parts if everything is in spec.

oldnavy · **Posted:** Fri Jul 28, 2006 9:11 pm

Reggie wrote:

I could well be related to fuel pressure but if I was to hazard a guess it could be that those of us with low fuel economy have our operating specs on the low end of what ever has an adverse impact on fuel economy. It might be that our fuel pressure, valve timing, and crank position signal are ALL on the low end, but still in the operating window. Because everything is within spec the dealer won't fix it. Actually it would be next to impossible for the delaer to get STAR to authorize the parts if everything is in spec.

Wrong answer, the MPG's are not in spec. That negates the nothing covered rotuine.

Fuel mileage - 1st tankful

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