Hoping to exceed 40 MPG

IndigoBlueWagon said:

That's a manual versus automatic thing. Rob's tank range with an automatic is very good. Mine with a manual is just OK. I drive too fast to get really good range, at least most of the time.

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Yep, on the ALH cars it was always about a 5MPG bonus for the stick vs. the automatic.
I've always seen a bit of a dropoff in MPG the higher I go above 70 on the speedo myself, so I know where you're coming from with the "driving too fast" bit, IBW. The tank I showed above, I averaged around 70 on the highway miles, seems to be the sweet spot for me right now.
Back when I was still on the smaller stock nozzles I was averaging 44-45MPG under similar conditions (and even have two documented tanks at 47MPG).
To the O/P, I am glad the wife vetoed those "procedures" your shop recommended (since I doubt they will buy you dinner for that price, or ever call you later ).
IBW's probably right, the cooler temps are probably slowing the warmup (so maybe the pipe insulation grille block might help), but what pressure are you running on the tires now? I've always had tires whose sidewall max was 44 or 51, and I have found with my MKIV that around 38-40 was around optimum for ride/handling/grip/MPG. I recently had a rotation done and the shop that did it dropped me to 32PSI, which I only caught because I noticed a 1-2MPG hit at the next fill-up.
Another thing to check for is sticking brakes (at least the MKIVs are notorious for the parking brake mechanism in the rear calipers getting stuck and causing dragging) - a light drag can sap an MPG or two without being too noticeable in drivability. Of course, being winter it could have iced up too...

iluvmydiesels said:

but a few years ago i did my own EGR delete.
made my self a block plate.
at the same time i had my shop clean the intake,
after 2 1/2years, same power boost, its quite nice. maybe about a 7% power increase.

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i may want to go more conservative on my estimate, probably about a 4% to maybe a 5% increase in power, maybe some more.

iluvmydiesels said:

its quite nice. maybe about a 7% power increase.

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How did you compute a 7% power increase?

you can see, i backed off my estimate.
i figure it from giddy up. at 1/4 to 1/2 throttle i have noticeably more power. with more pedal too, i dont floor it too much. sometimes in higher gears.

iluvmydiesels said:

you can see, i backed off my estimate.
i figure it from giddy up. at 1/4 to 1/2 throttle i have noticeably more power. with more pedal too, i dont floor it too much. sometimes in higher gears.

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Butt dyno eh? If that is the case don't publish % just that it feels better and let it go at that.

srry if im using a %age estimate from the back of my seat, for a stock engine, with the work i did, its a significant power boost. not a h*ll of a lot, but noticeable. intake was normally, quite choked, $50 over-night cleaning. ports were open, was a new head i put on. a good & noticeable boost.
maybe next week i ll put on a new, better head, possible i get some porting and polishing done, and possible valve angle job, well see.

When I went from the 4 Speed O1M auto to a 5 speed manual (2000 ALH Beetle), I picked up 8 MPG, easily. Now, with RC 2 on the Beetle, I STILL can get 45 MPG without trying too hard - I snap off 600 mile tanks (highway) without blinking, and I have even made 700 miles for one or two tanks.


2015 Golf with the DSG lags some on the MPG compared to the Beetle, but I can still pull 40MPG + highway at 75MPH + .

Lightflyer1 said:

An injector purge might help if you have a lot of miles on the car.

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It seems that the instructions on the link you suppled would not apply completely with my NMS. and based on this thread (http://forums.tdiclub.com/showthread.php?t=492810), it is either not possible because of the location of the fuel pump in the tank, or not needed because of gains with diesel technology and ULSD. So like Fastbird, I poured the Liqui Moly in the tank. It won't hurt and should do some good. Besides, I wasn't experiencing any issues, just looking to maximize my MPGs. Thanks anyway.

It can still be done you just have to adapt for the newer car. Good luck on your search for better fuel economy.

I had a wreck in my 06 Jetta and was able to find a 2015. The recall modifications have been done, and to my surprise, MPG improved slightly. In Phoenix metro traffic I am getting 38-40 and last tank of Hwy MPG traveling from AZ to midwest in November I had mixed tanks of 44mpg low to 49.9mpg. I am really pleased.

44mpg to ~50mpg?? thats great mileage for a newer TDI, and recalled.
my ole MK2 IDI worn out and freshened when i ran id get 47 or 48.

Update as of 4/30/19

In case you didn't see my OP. My goal was to get to 40 mpg without changing the way my wife drives too drastically if at all. Well my last four fuel-ups have been 39.04, 39.11, 39.89 and 43.06! The only things I did was to inform my wife that the speedometer doesn't jive with the GPS. When the speedometer says 75 mph the GPS says she's doing 77-78. So now she sets the cruise at 2 mph lower on the highway to achieve the posted speed limit. I also have been adding Stanadyne to each gas tank as well at trying to use Top Tier gas or Shell, both of which are available on her commute. The last two fuel-ups included a trip to MO for my daughter's college visit as well as some of my wife's regular commutes. i'm looking forward to many more 40+ fuel-ups. Hopefully on a regular basis. Fuelly has my composite at 38.1 mpg which isn't too shabby either.

Slowing down to 65 will result in an even better MPG jump. If she does the trip math slowing down even a little bit usually doesn’t result in significantly longer trips unless you’re making really long highway trips. It all comes down to what a few minutes are worth.

Given that you’re in Salina coasting down hills is not an option. Ain’t many hills in Central Kansas.

Here's some Euro/UK MPG figures. A lot of freeways here are being updated, roadworks/construction limits means long stretches at 50 mph, reinforced by 'average' speed cameras. So most people crawl along at 50 mph on cruise in the construction zones, if they have it.

Latest 'best' figures from my 2016 Jetta TDi Bluemotion are 79 mpg (UK) = 65.7 mpg (US). This is at 50 mph on cruise for 10 miles. No-one travels at 50 mph, unless there are speed cameras.

Engine is the 2.0 CR, but the 'eco' 110HP BlueMotion DSG7 SE model. 'Coast mode' turned off.

Our highway national speed limit is 70 mph, though 80 mph is the going rate. At 70-75 mph on cruise over long distances the Jetta does 54+ MPG (US), 65 MPG (UK).

The Jetta seems more 'slippery' than other DERV's I've owned. Also has 'eco Dunlops, at 44PSI. The occasional 700 mile tank range seems possible.

Gettajetta said:

The Jetta seems more 'slippery' than other DERV's I've owned. Also has 'eco Dunlops, at 44PSI. The occasional 700 mile tank range seems possible.

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We just finished an 800 mile road trip in our BMW 540d...to Montreal and back.Started with a full tank (17.2 US gallons),didn't buy a drop of fuel while away,and when we got home the "distance to empty" reading was 15 miles.About 700 miles of the trip was at a steady 65mph and the other 100 were under bad conditions (torrential rain,stop & go,lost,etc)

The actual MPG (not the onboard computer reading) was 47.02 (US).


Our "d" is much bigger and heavier than a TDI. The discrepancy is curious IMO.

Lightflyer1 said:

I went 806 miles on 15 gallons in my 2006 Jetta. Mostly 60 mph the whole way. 53 mpg. Round Rock to Fort Stockton and back just to test the highway economy of the 2006 Jetta when they were new.
http://forums.tdiclub.com/showthread.php?t=134473&highlight=stockton
There are a lot of things you can do to increase your fuel economy, but if the cost of them is more than just buying a little more fuel, what is the point. If I put $2 of additive in just to get a few more mpg how is that better than just buying $2 more fuel? Tuning as well. Paying $600 for a tune would take a very long time to recoup the cost. If a little effort to drive better won't work then I just wouldn't worry about it.
When my warranty runs out or if VW gives me any grief in regards to repairs under warranty, I will probably delete emissions and tune. But the warranty is one of the reasons I bought the car in the first place, so I don't take voiding it lightly.

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I'm catching up on some of these threads, as I'm new here, but this post sums up how I feel perfectly. Well stated.

Warner