Any one elses MPG Dropping??

[mmalluck]

ULSD fuel does have less energy content, but it's only 1% less than regular LSD. That would only account for a .5mpg drop. I blame hot weather for conserable more loss.

 

[8606]

"I blame hot weather for conserable more loss." I now think that is the biggest reason. I have been running the ac at its coldest setting for a while now. MPG has dropped as low as 40.32 mpg(40.88mpg last time with PowerService gray). Yeah I don't like the drop , but having ac and being comfortable is more important to me than a mpg drop of 1 1/2%-2%.

 

[fish_on]

56k on my 05.5 and my mileage has been down slightly the last 2 weeks (6 tanks of fuel) 49mpg to 42mpg. I have been running the a/c more but it seems to be a pretty big drop.

 

[Leedogg]

56k on my 05.5 and my mileage has been down slightly the last 2 weeks (6 tanks of fuel) 49mpg to 42mpg. I have been running the a/c more but it seems to be a pretty big drop.

I don't feel so bad now....only got 37.8 on my last tank(80-ish mph indicated)....down from a 41 average when it was cooler. I too will gladly give up 3 mpg in this heat....black car + deep south= HOT...but I still love the color choice.

 

[LILALLEYKATT]

I just did a top end run in southern Tennessee and pulled 124M.P.H. on the speedo. My Garmin gps indicated 119M.P.H.. I thought Jettas were sopposed to be governed to 114M.P.H.. I feel like my Jetta is worth 125M.P.H. actual because it was still pulling when I backed off..Oh yeah I was getting 10Mpg...LILALLEYKATT

 

[Kirtwell]

I'm glad I read this post now...I was beginning to think something was wrong with my car....I have 70K on my 04 Golf (Auto Trans) and I typically get between 40-43mpg religiously! I took a job that requires me to drive 99% highway 85 miles one way and I'm only getting consistant 37-38.5 mpg. I live in Oklahoma and drive into Texas...the temps have been 100-105 every day for weeks... so I'm running the A/C full blast

I'll keep checking mine and hopefully when the temp drops in the 80's I'll see some improvement.

 

[shaark92]

Ditto 'QM'

I will double check. My wife works in the Petroleum Industry and will be able to source this out with the major carriers.

I really hope you're wrong Quartermeter - for all the right reasons! Unfortunately, I am afraid that you are either right, or a bunch of us are losing mpgs for no apparent reason.

Rob

Just completed a 700 mile trip which began with ~1/2 tank (refuel necessary) ... unintentionally got the ULSD during the refuel. Indicated mileage has dropped from ~48 mpg to ~41. Have yet to verify w/ calculator (even @ 41 mpg, have yet to burn it out)

4600 miles on the Jetta

(Vag Com/Bentley ordered in prep for oil change)

Al

 

[Highline]

Recently I had a tankful that seemed to give me a little less power. I could barely muster up black smoke for tailgaters and my mileage was down about 7%. I had a feeling it was ULSD but can not prove it.

You know, I love being able to kick out black smoke for tailgaters. I have never been able to do that before

 

[DieselDavid]

You know, I love being able to kick out black smoke for tailgaters. I have never been able to do that before

Oh yes I agree completely. Almost daily I find myself driving in the rightmost lane of a highway going 5 to 10 MPH above the speed limit when another car comes up behind me. They tailgate, they flash their high beam headlights, they sometimes wave their hands around and have angry facial expressions. Hey, I'm in the rightmost lane already speeding a bit - they should pass mein one of the other lanes to our left! Well, often in these cases I downshift and floor the accelerator. A nice dark cloud shoots out the exhaust tips. I'm sure that cloud of diesel exhaust smells really good (heavy sarcasm)...! Note: we can't do this often because it takes a bit of driving to build up some nice soot particles.

Back to the topic of this thread. My average fuel economy has dropped slightly too. This does not upset me too much because I am still getting great fuel economy relative to all the other cars I've owned past and present, and great fuel economy relative to most of the other cars on the roads. Also in my area at this moment (i.e. the summer) the least expensive stations are selling diesel for less than they are selling low octane gasoline. At these stations diesel is between 13 cents and 28 cents per gallon less expensive than low octane gasoline.

 

[Bob_Fout]

I just did a top end run in southern Tennessee and pulled 124M.P.H. on the speedo. My Garmin gps indicated 119M.P.H.. I thought Jettas were sopposed to be governed to 114M.P.H.. I feel like my Jetta is worth 125M.P.H. actual because it was still pulling when I backed off..Oh yeah I was getting 10Mpg...LILALLEYKATT

Should have been about 25 MPG at top speed.

 

[Leedogg]

lilalleykat- I hit 123 last week myself(indicated). Found mysel cruising with an Infinity G35 who was hauling the mail too...we stretched em out for about 30-40 miles at 105+mph...car cruised it like it was cool! I know that guy had to be thinking- 'dang I didn't expect a lil VW to keep up at 120'.

 

[Frank M]

I quit at 58mph

I just did a top end run in southern Tennessee and pulled 124M.P.H. on the speedo. My Garmin gps indicated 119M.P.H.. I thought Jettas were sopposed to be governed to 114M.P.H.. I feel like my Jetta is worth 125M.P.H. actual because it was still pulling when I backed off..Oh yeah I was getting 10Mpg...LILALLEYKATT

I had my 1200cc 40hp 1965 Beetle out the other day.
I met a Ferrari Testarossa and he wanted to go.
I quit at 58mph because I could not see him any more.

 

[Highline]

I had my 1200cc 40hp 1965 Beetle out the other day.
I met a Ferrari Testarossa and he wanted to go.
I quit at 58 because I could not see him any more.

In my book you get a big A+ for effort!

 

[JGordon]

''Same here, went from 41mpg to 38mpg. I've got 4200 miles on the clock, all city driving, always fill up at the same station, blah blah blah. I did notice the drop right about the same time they put the sticker on the pump saying that the diesel in the pump was illegal for 2007 and newer vehicles...''








I noticed my fuel mileage drop since the low sulfur fuel also, first trip babying the hell out of it with no A/C I got 53.75 mpg with very little city driving before the low sulfur sticker on the pump.


Second trip I got 44 mpg with the A/C with city driving added into the mix.

Third trip was about identical to the second trip; with a little less A/C.I got 38.1 mpg I have about 18000 and change on this car and it has fresh oil/fuel/air filter installed on this tank.

I believe this fuel is the culprit, because I actually was trying to get 50+ mpg on this tank with minimal A/C.


I asked a friend that drives a 1-ton 4 WD Duramax if he has noticed any difference in fuel mileage since the low sulfur hit the stations. (He said “now that you mention it has dropped from 18 mpg to 16 mpg)

This guy is as anal as I when it comes to checking fuel mileage.

 

[Mach1]

I dont feel so bad about my 44mpg every tank then, its right at 100 here so the AC gets max usage, but I have been trying to keep it at 72...I did notice the low sulfur fuel though. 500ppm.

 

[DieselDavid]

I changed the way I use the AC also. In the past with my other cars I'd put the temperature control on the coldest setting when using the AC during hot and humid weather. At first I did the same with my TDI. I quickly realized the climate control system is fairly accurate. Recently I started adjusting the temperature control from "Lo" to an actual temperature, just like the way we do it with the thermostats in our homes.

Yesterday it was slightly over 100 degrees F here. At first I had the AC temperature control on "Lo." After 10 minutes the car was comfortable and I changed it to 68 degrees F. I was still comfortable. Maybe this caused my AC system to work a little less while still keeping me confortable - and thus not robbing my fuel efficiency too much?

 

[Frank M]

more than the usual power and better mileage

What is interesting to me is, I had experienced poor performance and mileage on a couple of tanks I got at one station.
I then went to another station and for the next two tanks I had more than the usual power and better mileage than previous.

I have since got my last tank at a third station, and it is comparable with the second station.

Maybe some oil companies are different or the amount of additive added varies, hopefully until they get it right.

 

[buckeye96]

I keep my AC on 74 all the time so wouldn't my mpg be better?
Cause I am still seeing a huge hit in efficiency

 

[mmalluck]

I keep my AC on 74 all the time so wouldn't my mpg be better? Cause I am still seeing a huge hit in efficiency

Still depends on the length of your trips. With short trips not only do you have to heat up a cold engine, but you have to chill a blazing hot interior every time you start the car back up.

If the thermostat works like a standard one the AC will run flat out until it gets to the set temperature. Only then will it cut out and regulate the temp.

Hot weather also makes the intercooler and radiator less efficient, leading to a less efficient engine. Hot intake air means less air and fuel per stroke, so you need more strokes to get the job done. A hot cooling system means more running of the fans to keep it cool.

 

[Mach1]

I have been experimenting with the recirc position, On the older vehicles it closes the outside air off and recircs the interior air. I am not sure if it works in conjuction with the temp control or not.

Yes the oil companies are messing with the mixes right now big time, They are blending in the ULsd, lsd, and they are getting crude from all different places because of the cost difference on a day-to-day basis the crude can vary a couple of dollars. The BTU content is going to vary as where they get there crude from, There are deals on different batches of crude and we are going to see those differences in our FE.

I try to find a station that has consistantly good FE from the diesel, then I dont mind paying the $.5-.10 gallon more, as long as I can get max FE, it pays for itself to spend the extra money and then get all the miles from the better fuel. so just because you see inexpensive fuel doesn't mean yo uare getting a deal, seems like it up front, but when you lose 10% on your FE. then you actually lost money. I can tell almost immediately.

 

[two.marek]

My MPG get down too.
I think the fuel is the main problem.
I have overheard about intentional lowering diesel fuel quality in order to keep gasoline prices down.
Any one can explain to me why diesel fuel is so expensive compeer to gasoline?
Any way, A/C is the factor, but in the past I did not see so dramatic changes.

___________

 

[TDI 4 RD]

My MPG get down too.
I think the fuel is the main problem.
I have overheard about intentional lowering diesel fuel quality in order to keep gasoline prices down.
Any one can explain to me why diesel fuel is so expensive compeer to gasoline?
Any way, A/C is the factor, but in the past I did not see so dramatic changes.

___________

Just to add my experience: I was averaging about 42 mpg (4000 miles). The lowest I had seen was 38. This past week, my mileage dropped to 33, but not with any change in my driving style or conditions. I use Stanadyne with every tank. Ugh.