[DreiD]

See Sig.

She got 38.4 on the way back home (Texas) from being picked up in Florida.

[Brad335d]

Everyone says the computer will read a higher MPG with the JBD installed.

As stated by a few others here, I've found this to be false.

I run the JBD at 100% and on my road trip stated earlier in this post the on-board average MPG was indicating 34 MPG. When filling up I hand calculated the MPG and it was 37.xx MPG.

This is not the first time I've found the on-board MPG to be reading lower than the actual MPG.

[335dFan]

Originally Posted by Brad335d

Everyone says the computer will read a higher MPG with the JBD installed.

As stated by a few others here, I've found this to be false.

I run the JBD at 100% and on my road trip stated earlier in this post the on-board average MPG was indicating 34 MPG. When filling up I hand calculated the MPG and it was 37.xx MPG.

This is not the first time I've found the on-board MPG to be reading lower than the actual MPG.

I hand calculate every tankful, and I have never once seen the computer higher than my hand calculations. To be fair, I don't pay much attention to what the computer says, with the exception of being interested in how many miles it thinks I have left in the tank. Which I have to assume is using some of the same algorithms as the MPG.

[Vreimann]

Originally Posted by 335dFan

I hand calculate every tankful, and I have never once seen the computer higher than my hand calculations. To be fair, I don't pay much attention to what the computer says, with the exception of being interested in how many miles it thinks I have left in the tank. Which I have to assume is using some of the same algorithms as the MPG.

I find the same thing.

For my travels to the US recently we drove a lot and I reset the trip computer just after leaving the city and the overall mileage recorded by the car was 7.5l/100km (31.2USMPG) and the hand calculated is 7.16l/100km (32.9USMPG)
Not much a difference. But it is a difference.

[GreekboyD]

Will be even better after my DPF delete/EGR off and SCR/DEF removal.

[doc5339]

Originally Posted by Brad335d

Everyone says the computer will read a higher MPG with the JBD installed.

As stated by a few others here, I've found this to be false.

I run the JBD at 100% and on my road trip stated earlier in this post the on-board average MPG was indicating 34 MPG. When filling up I hand calculated the MPG and it was 37.xx MPG.

This is not the first time I've found the on-board MPG to be reading lower than the actual MPG.

My trip computer read a lower MPG than hand-calculated prior to JBD installation, and it still reads low; computer says 32 MPG, hand-calculation shows 34 MPG

[Thud]

These days I only have a 10 mile commute, which is about 4 miles in town (traffic) and 6 miles highway (70+ mph). Calculated avg per tank is around 24.5mpg. I used to get 28-29mpg when I had a longer commute with more highway.

I also lost about 1mpg when I got new tires (Michelin PS2 runflats) because new tires with thicker tread have higher rolling resistance. That made me realize why so many people say the mileage improves on these cars during the first 10k miles of ownership-- it's actually the tires wearing out!

[335dFan]

Originally Posted by 335dFan

Another thing I have recently noticed. I have been using the A/C non-stop since I bought the car. So that is a factor in my mileage. Recently my A/C belt has started to squeal a bit on startup, so because I am in no mood to take the time to take it to the dealer (and remove my JBD, etc.), I have started running without the A/C, even though it has been rather warm lately. I just run with the windows down. Hey, I lived in Singapore for 6 years so the heat doesn't bother me. Anyway, I haven't done a full tank yet w/o A/C, but I have noticed that the computer is telling me I am going to get about 580-590 miles on this tank, whereas before with this kind of driving I would be around 500-510 on a tank. Will report when I refill next, and probably keep doing it for a tank or so just to confirm.

OK, well, my first full tank since not using the A/C gave me an extra 1-2 mpg I guess. Not so much. One tank does not the story tell. But am pretty consistent in my suburban driving habits and that is roughly what it seems to be worth for me.

[D2011rcs]

Just got my D less than two weeks ago. In mixed driving - 20 mile commute, mostly highway, but with some stop and go, looks to be appx 30. I wish there was a proper temp gauge to see how quickly the engine reaches operating temp but that will likely be a bigger issue when the winter hits. Have other folks noticed a drop off in efficiency in the winter? If so, how much?

[335dFan]

Originally Posted by D2011rcs

Just got my D less than two weeks ago. In mixed driving - 20 mile commute, mostly highway, but with some stop and go, looks to be appx 30. I wish there was a proper temp gauge to see how quickly the engine reaches operating temp but that will likely be a bigger issue when the winter hits. Have other folks noticed a drop off in efficiency in the winter? If so, how much?

It's hard to tell. Our vehicles seem to warm up rather quickly. I suppose my mileage did improve somewhat with the warmer weather, but that probably was because I was taking longer trips when the weather improved. The weather in MD this winter wasn't very cold anyway.

[floydarogers]

Originally Posted by 335dFan

... Our vehicles seem to warm up rather quickly. ...

TDIwyse has done a lot of data gathering, including temps. Actually the diesels warm very slowly, and in winter sometimes never. Remember we have an electric element in the hvac for that reason.

I'm going to link to a couple threads in bimmerfest - they link to e90post so why not the reverse.
http://www.bimmerfest.com/forums/sho...1&postcount=10
http://www.bimmerfest.com/forums/sho...ight=cardboard

[Puerto Rican 335d]

Since changing to new diesel American Petroleum a.ka. 76 Im getting better milaege along with the air scoops I added to the car, so, frankly dont know if both combined or the diesel or scoop has helped me

[335dFan]

Originally Posted by floydarogers

TDIwyse has done a lot of data gathering, including temps. Actually the diesels warm very slowly, and in winter sometimes never. Remember we have an electric element in the hvac for that reason.

I'm going to link to a couple threads in bimmerfest - they link to e90post so why not the reverse.
http://www.bimmerfest.com/forums/sho...1&postcount=10
http://www.bimmerfest.com/forums/sho...ight=cardboard

Sorry to pass along factually incorrect info on the speed of warming up, even as just an armchair observation. I don't know about the rest of you fellas, but I do use this forum as one, but not the only, source of information to make my decisions about my D. And it does take some time to sift through all the different inputs until you come to a point where you feel comfortable about taking a particular course of action.

[floydarogers]

Originally Posted by 335dFan

Sorry to pass along factually incorrect info on the speed of warming up, even as just an armchair observation. ...

I'm sure our aluminum-block diesels warm up quicker than an iron-block Cummins or whatever.

I'm glad you didn't take my pedantic OCD'ness correction personally.

[335dFan]

Originally Posted by floydarogers

I'm sure our aluminum-block diesels warm up quicker than an iron-block Cummins or whatever.

I'm glad you didn't take my pedantic OCD'ness correction personally.

There is enough contentiousness in the world already without taking offense at something somebody says on a forum. You'd think our family honor was at stake the way some of these exchanges go.

[tony20009]

19.6 is what the car is showing when I was last in it at the start of the week. If my son drives it, which only allow for special reasons, it might drop down to about 18 or 17 mpg. If I try really hard to keep my right foot in check, I can eke out 21 in the city.

On my last longish trip, I got 29 mpg.

[335dFan]

Originally Posted by tony20009

19.6 is what the car is showing when I was last in it at the start of the week. If my son drives it, which only allow for special reasons, it might drop down to about 18 or 17 mpg. If I try really hard to keep my right foot in check, I can eke out 21 in the city.

On my last longish trip, I got 29 mpg.

Sorry, no gassers allowed in the diesel forum. It's just not fair to you petrol-heads.

[Hoooper]

Originally Posted by Thud

I also lost about 1mpg when I got new tires (Michelin PS2 runflats) because new tires with thicker tread have higher rolling resistance. That made me realize why so many people say the mileage improves on these cars during the first 10k miles of ownership-- it's actually the tires wearing out!

True. Fuel mileage is just another good reason to ditch these crappy heavy runflats once they wear out. You can easily save 3+lbs per tire and with some you can save up to 5 lbs per tire. Doesnt sound like a lot but 10 lbs off the driven wheels is nothing to scoff at. Plus you get the added benefit of better traction and comfort

[tony20009]

Originally Posted by 335dFan

Sorry, no gassers allowed in the diesel forum. It's just not fair to you petrol-heads.

Oh, I'm sorry. I clearly read only the thread title and responded. Would you like me to delete my post?

[335dFan]

Originally Posted by tony20009

Oh, I'm sorry. I clearly read only the thread title and responded. Would you like me to delete my post?

Just kidding, a la the wink icon. We bow in humble deference to the power of the 335i, except when we are passing you while you are gassing up at the filling station.

[tony20009]

Originally Posted by 335dFan

Just kidding, a la the wink icon. We bow in humble deference to the power of the 335i, except when we are passing you while you are gassing up at the filling station.

[tony20009]

Originally Posted by 335dFan

Just kidding, a la the wink icon. We bow in humble deference to the power of the 335i, except when we are passing you while you are gassing up at the filling station.

I'll keep that in mind if I find myself hosting an event for DC/MD/VA Bimmerpost members in which case I'll be unremorseful about choosing a venue closer to DC than to Annapolis.