Real World MPG - 6 speed Manual

[rotarykid]

Between the last day of running on the "Old" fuel and the next day of using the Sunoco there may have been a difference of five -seven degrees F to which if the temps went down I would see an MPG swing go down one maybe two MPG. In this instance the temp rose (Mid 30's-low 40's F) and the MPG increase was drastic-over 10MPG.

I do have a fairly competent grasp of engineering practicum though my experiences in diesel theory are solely with my TDI-Yes, much to learn. Looking at my data logging on fuelly.com is missing at least the outside temperatures enabling a foundation for analysis.

My thoughts ran trying to point to the contributing variable- fuel brand that MAY have been the sole cause. Non the less, I'm staying the course with using the Sunoco brand and paying the inconsequential premium (< $3 variance per tank full) to achieve these improved and desired results.


2012 Passat TDI SE. 6SpM-Black/Black/Dark Tint

You can soften the impact to mpgs by adjusting driving style for temp changes to colder temp ranges during warmup period.

Driving easy when the engine is cold is the easiest way I know to save fuel. The warm up time varies with ambient temp changes. This is the time when the engine uses the most fuel. Hard driving while warming up waste fuel from the engine being over fuel and the dumping of fuel directly into the exhaust to get all the emissions crap functioning as quickly as possible.

The harder you drive the car when it is still warming up the more fuel will be just dumped into the exhaust to get it up to normal temp giving no energy to moving or powering the car killing mpgs. By driving the car easy you less fuel and less fuel will be wasted from the ecu over fueling. Avoiding overrun when cold can reduce it just dumping fuel into the exhaust flow.

First; IF you have a manual trans car using momentum(gravity) to start the car can reduce battery drain on starts. The first start of the day costs a couple of mpgs for a period of time to replace battery drain. The colder the temps are the more fuel is used recharging from that start with the starter.

By Using a slight down grade out of your garage or driveway for the first start of the day after allowing the engine a glow cycle or two can make a big difference in the tank average mpgs. I have clocked as much as a 5 mpg difference, savings from using a rolling start for the cold start of the day!

During warm up period Keeping load as low as conditions allow and keep rpms as low as conditions allow you will save fuel.

Coasting in N, not allowing over run which is the time when the most fuel is wasted today by our engines in warm up( this is when the ecu dumps fuel into the exhaust stream for exhaust system heating ),

In a manual trans car while the engine is still cold or in colder temps when the engine is warmed up the killing of the engine while coasting in N over rolling or hilly terrain can save a lot of fuel. Then using built up momentum to restart the engine saves of energy drain that would be needed if the starter is used.

I would avoid doing this in higher ambient temps because of the extra turbo built up heat. Killing the engine in these conditions can lead to oil coking up issues....

Conditional awareness not to over accelerate in traffic just to have to use the brakes to kill built up speed. Avoiding brake use as much as conditions allow saves momentum which is previously burned fuel.

The skipping of gears in a manual, using the manual shift mode in a DSG to go through without using unneeded gears only using the ones directly required. 1st, 3rd, 5th or 6th can be all you need most of the time. Not running the rpms up above 2k from starting out then shifting to get the rpms to just above idle for the next used gear. Then once desired speed is reached get into high gear and stay there until acceleration is required again....

If you can learn to balance this out you can learn to just use the generated engine heat over a longer period of time to get the exhaust system up to proper temp....

 

[ZootsAlures]

Where I usually practice consistent driving techniques and methods there's always room to improve ! Kaisen !!

Startup techniques are heavily biased in the New England area in the pre to post winter persona. If I awake to fresh "Precipitation" I go right into DEFCON 1 to warm and clean up prior to departure. It's a forecasted consideration of the OpEx component of the budget?


2012 Passat TDI SE. 6SpM

 

[rotarykid]

Where I usually practice consistent driving techniques and methods there's always room to improve ! Kaisen !!

Startup techniques are heavily biased in the New England area in the pre to post winter persona. If I awake to fresh "Precipitation" I go right into DEFCON 1 to warm and clean up prior to departure. It's a forecasted consideration of the OpEx component of the budget?


2012 Passat TDI SE. 6SpM

BEing in Colorado a lot of the time, I am well aware of icing issues that can interfere with the rolling start up. But there are enough ice free or ice free enough days here to see benefit from using gravity to start the engine. And You would be surprised how much traction you can actually get for a rolling start in third gear on packed snow.....

It is very rare that rolling start is not possible during winter conditions in my VW diesels. In fact over the last 20+ years I can only think of a handful of times in Colorado snow when icy conditions that were too slick forced me to use the starter....

And I am not saying drive easy all the time, just during that very small window of warm up. Once normal temps are reached you can give the engine the needed revving to keep things in the emissions crap working unclogged without the extreme mpg penalty suffered while warming up....

 

[psd1]

. Looking at my data logging on fuelly.com is missing at least the outside temperatures enabling a foundation for analysis.

My thoughts ran trying to point to the contributing variable- fuel brand that MAY have been the sole cause. Non the less, I'm staying the course with using the Sunoco brand and paying the inconsequential premium (< $3 variance per tank full) to achieve these improved and desired results.

So change your methodology and add temps when you fuel up. I consider and add an average AM and PM OAT in the "note" section of my fully account. If you do this, I'm pretty certain that you will be able to determine that the OAT was the contributing factor to your MPG loss, it could also save you +/- $3 per tank.

My guess is that you will do what you want and continue to fuel at the more expensive station. To each their own.

 

[PassatSE4me]

Well the cold and a majority of city driving killed my last tank. Only got 37. Listen to me… only. Lol

 

[psd1]

Well the cold and a majority of city driving killed my last tank. Only got 37. Listen to me… only. Lol

Thank goodness the weather here has warmed up...filled up today and returned 48.3 MPG.

 

[psd1]

Filled yesterday, 790 miles/16.20 gallons of fuel. 48.8 MPG. Very pleased!

 

[matty-matt]

First tank, leaving dealership in Baltimore and arriving in Louisville at 74mph average speed (including 40 minutes of rush hour bumper to bumper) gave 39mpg.
On second tank now, after Malone 1.5 tune and H&R Sport Spring instal, got 47mpg at 66mph average for 140 miles.
Not sure how much is tuning, lower speed, lower drag from being 1.5" lower. But not complaining!

 

[psd1]

First tank, leaving dealership in Baltimore and arriving in Louisville at 74mph average speed (including 40 minutes of rush hour bumper to bumper) gave 39mpg.
On second tank now, after Malone 1.5 tune and H&R Sport Spring instal, got 47mpg at 66mph average for 140 miles.
Not sure how much is tuning, lower speed, lower drag from being 1.5" lower. But not complaining!

Man, you couldn't even wait to get a baseline on that thing huh?

Do you mind sharing the details of the tune and maybe some pictures of the car?

 

[matty-matt]

nope. want to get it sorted out while it's fresh!
happy to post some photos if it ever gets above freezing and i can get the salt off it.
tune is basic Malone 1.5 documented elsewhere. very noticeable torque increase but not as much as i had hoped. it's no race car....
put Michelin Primacy's on it yesterday, local tire shop i work with gave me $250 for the Hankooks.
cost $500 out of pocket. definite improvement in handling and noise. hopefully mileage is same or better.

 

[matty-matt]

oh, here's a pic Dax took this weekend right after the spring installation:

http://forums.tdiclub.com/showthread.php?p=4416725#post4416725

 

[psd1]

Last tank 49.0 MPG.

 

[sandmansans]

Sent from my VS980 4G using Tapatalk

 

[DmaxSmoke]

My MPG has dropped a lot w/ subzero temps, I am not entirely sure how badly, since I stopped tracking my fill ups, but its still in the upper 30's with a lot of city and stop/go driving. Much better than driving my truck.

 

[gwalter]

I'm getting zero MPG. Just bought a 2014 TDI SE. Can't wait for the 50 mpg days.......

 

[psd1]

I'm getting zero MPG. Just bought a 2014 TDI SE. Can't wait for the 50 mpg days.......

I know the feeling. You can look at my fuelly from one year ago when I bought our 2013. I was very anxious those first few tanks.

 

[matty-matt]

Just completed 940 mile trip from southern indiana to central florida yesterday.
left at 5:10am, arrived before 6pm, EST.
mileage for trip was 41.7 at 72 mph average.
one stop for fuel and quick bathroom break in GA.
did not expect to comfortably be able to do trip in one sitting but it was easy!

 

[gwalter]

Should be getting the new car this week. Then the MPG tracking begins!

 

[matty-matt]

return trip from Daytona Beach to Southern Indiana, 970 miles, 42.7 mpg at 75 mph average.
Malone tune makes downshifting from 6th unnecessary for passing even up hill in mountains.
LOADED with three people and trunk and backseat completely packed with luggage. suspension was definitely pretty well maxed in back with top of tires hidden but handled great.
H&R sport springs & rear sway bar make car feel taut and controlled compared with stock.
overall very pleased with setup

 

[psd1]

Last tank 816 miles and 16.4 gallons. 49.8 MPG

 

[IXLR8]

Between the snow tires, the winter fuel and the #%@^ cold snowy weather I am only getting about 45 mpg's. I can't wait for warmer temperatures and putting the summer tires back on and get back to what passes as normal mpg's.

 

[psd1]

Between the snow tires, the winter fuel and the #%@^ cold snowy weather I am only getting about 45 mpg's. I can't wait for warmer temperatures and putting the summer tires back on and get back to what passes as normal mpg's.

Holy crap, you're getting hammered! What a suck fest to go from 1000+ mile tanks to 800. Terrible that we can complain about 45 MPG! Ha Ha HA!

 

[IXLR8]

Holy crap, you're getting hammered! What a suck fest to go from 1000+ mile tanks to 800. Terrible that we can complain about 45 MPG! Ha Ha HA!

So you checked my fuelly data. Yes... hammered is a good way to put it. The snow tires are good for 3-4mpg of the hit, temps are a big factor as well. I have never owned a car that the mpg's were more sensitive to temperature than this car. With the exception of my trip to NC last September, if you compare my fuel economy to the average temperature here there is basically a one to one correlation. My lowest mpg's exactly correlate to the lowest temps that we have experienced this winter and last. My highest mpg's have been when the temps have been the highest last summer.
How many other vehicle owners can complain when their mpg's drop DOWN to 45 mpg's.

 

[psd1]

So you checked my fuelly data. Yes... hammered is a good way to put it. The snow tires are good for 3-4mpg of the hit, temps are a big factor as well. I have never owned a car that the mpg's were more sensitive to temperature than this car. With the exception of my trip to NC last September, if you compare my fuel economy to the average temperature here there is basically a one to one correlation. My lowest mpg's exactly correlate to the lowest temps that we have experienced this winter and last. My highest mpg's have been when the temps have been the highest last summer.
How many other vehicle owners can complain when their mpg's drop DOWN to 45 mpg's.

Temps have absolutely correlated to MPG's with my Passat as well. I keep temps in the "note" section on fully.

 

[gwalter]

Only 4 fill ups so far. Overall average is now 43. Very cold out, a fair amount of local driving, brand new engine that I'm trying to rev up and down for break-in purposes are likely my issues. Also trying not to drive around using the MFI's suggested gear. Feels odd to be chugging along at 1100 rpm and when you need a little more fuel I just can't do it in that taller gear. Running 1400 to 1500 rpm makes more sense to me.

 

[psd1]

Only 4 fill ups so far. Overall average is now 43. Very cold out, a fair amount of local driving, brand new engine that I'm trying to rev up and down for break-in purposes are likely my issues. Also trying not to drive around using the MFI's suggested gear. Feels odd to be chugging along at 1100 rpm and when you need a little more fuel I just can't do it in that taller gear. Running 1400 to 1500 rpm makes more sense to me.

All of the above isn't helping your numbers for sure. I looked at your Fuelly and noticed that all of your fills are very short. Even at 43-44 MPG's you should easily be in the 700 mile range. Your short fills are likely not helping your MPG's either. Don't forget that these cars have an 18.5 gallon tank even when my Low fuel light comes on I am generally only putting 15 gallons or so in.

 

[gwalter]

No doubt I have been short filling. I've been doing it purposely because I wanted to get an early glimpse at the accuracy of what I observe in the stats shown in the MFI vs what happens when I calculate MPG manually. I've been resetting the MFI to see how city vs highway driving goes.....just to see. I've seen some results where I'm getting 45 mpg around town. I've had some runs where the MFI told me over 50 on the highway too. Pretty soon I will be satisfied I'm passed the initial miles on the car that I can drive it any way I want. I think I can tell I should be able to get nearly the 50 mpg I was expecting.

 

[oswegoPD]

Another Polar Vortex coming to the Midwest. Finally saw some good MPGs on my commute when it got above freezing. I can't believe how much more sensitive these cars are to outside temps than my 04 Jetta was.

 

[psd1]

No doubt I have been short filling. I've been doing it purposely because I wanted to get an early glimpse at the accuracy of what I observe in the stats shown in the MFI vs what happens when I calculate MPG manually. I've been resetting the MFI to see how city vs highway driving goes.....just to see. I've seen some results where I'm getting 45 mpg around town. I've had some runs where the MFI told me over 50 on the highway too. Pretty soon I will be satisfied I'm passed the initial miles on the car that I can drive it any way I want. I think I can tell I should be able to get nearly the 50 mpg I was expecting.

What kind of driving will you be doing to expect a 50 MPG average? My driving is about 85% highway and my lifetime average is down to 49.9 MPG. I can't complain, and am looking forward to warmer temps to drive that lifetime average up. I'm hoping to have a 52 MPG average by the end of October of this year.

The problem you will see is that the extreme cold weather really hurts these cars. As long as you are experiencing temps under 20*, it's real hard to get much over 45 MPG.

Have fun and keep posting.

 

[muttmobile]

9642 miles and 224.805 gallons I am averaging 42.8905mpg so far.
I dont think that is too bad considering half of the mileage was during 30 below temps and two of those tanks were below 10 deg. Those two 10 deg tanks barely hit 40mpg.