REAL NUMBERS in MPG - need ideas for improvements

BEEnTDI

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hey gang!

I feel like this topic's been discussed to death already, but I can't seem to be amazed by some of the mileage of some folks on here, and feel this sudden urge every time to know their "secret".

58-59.5 MPG - really??? - Can some of your 60mpg folks PM me? I'd love to have the ability to talk to a

I've heard people and 1000k mile clubs .... 1012 miles/tank (14.5g)? What the hey - over 69 mpg?

We recently purchased our first VW TDI and we love it. I try to follow every rule possible and every advice.

- Bought this as a 2006, even though I later realized it was a 2005 model.
So

2005 TDI GLS - 95k miles
Triptonic gearbox

REAL NUMBERS (city driving):
- 20 mile drive 1-way (40 total/day)
- 1 hill on the way (down/up) ~2 mile 5% incline
- PSI tires - as specified (33 front - 42 back)
- 15 PPM sulfur diesel gas
- below 2400 RPM shifting point (all gears)
- only drive it in manual mode
- try to keep the RPMs around 2k

45.5 MPG or less

Not sure about highway yet.


So - after reading a whole bunch of contradictory posts on this

What is the ideal driving style?
What should the shifting point be?
What is the most efficient highway speed?
What's the best MPG that one could expect from city driving? (my route for instance)

The most important - HOW on earth could I ever get close to 60MPG? Is that only on long trips?

Thank you so much for your input! I live off of these posts.

p.s. I didn't mean to be rude towards anyone - it just feels like too big of a difference in MPG.
 

BEEnTDI

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I normally set the cruise at 55, and on the downhill I try to hold the gas down to gradually increase the speed on the way down and then i let it do its thing on the way up.
 

LRTDI

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As you say, its been analysed to death. Definitely a case of read, learn, then put into action. You are starting with a disadvantage with an auto.

As for range, search ventectomy. A painless modification that allows you to increase your range at no cost.
 
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Joe_Meehan

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There is no magic bullet. It all has been discussed and is already here.

I should point out that miles per tank is not an good measure for a number of reasons including venting or lack of same and different size tanks in different cars.
 

BEEnTDI

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[/QUOTE]I should point out that miles per tank is not an good measure for a number of reasons including venting or lack of same and different size tanks in different cars.[/QUOTE]

I know a full tank is not a good measure, but that was a minor point i was making.
The 45.5 mpg i was seeing on my car - that was not based on a full tank of diesel, and neither were the other mpg rates i was giving.

I just can't seem to understand how someone can get almost 60 mpg and others only 40 or so with the same size/type engine.


I do appreciate the replies though and i continue to read threads, but just when you thought you found a good description, there's 4 or 5 other veteran members that contradict what was just said.

Don't know what to think ...
 

BEEnTDI

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LRTDI said:
...
As for range, search ventectomy. A painless modification that allows you to increase your range at no cost.

I'm not even concerned with range that much as i am with MPG.

I seem like i'm not really communicating very well.
The question i have is "how is the 10-15 mpg difference explained between similar vehicles? (engine size/type).

The Ventectomy might allow more fuel in the tank ... but doesn't quite explain in my mind the increased fuel economy.
 

40X40

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45 mpg is right on the money for an automatic of your vintage. Is your car a MKV or a MKIV? They have different transmissions, I think.

We generally quote MPG on a per tank basis, but not miles per tank.

If you get a scan gauge II, it can help you figure out how to drive your route a bit more efficiently. (it takes time....)

EDIT The vehicles are not perhaps as similar as you think, IE, manual vs auto is a big difference. EDIT

Bill
 

BEEnTDI

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Thanks Bill
40X40 said:
45 mpg is right on the money for an automatic of your vintage. Is your car a MKV or a MKIV? They have different transmissions, I think.
Are you saying i could not get 59 mpg no matter what the driving style?
I think mine's a MK IV.
40X40 said:
We generally quote MPG on a per tank basis, but not miles per tank.
I'm not sure what that means ... i measure it by dividing the miles done by the gallons i put in when i fill up. Even if the fillup doesn't stop at the same mark, in time it evens out. Discrepancies are quite neglijable. (I do happen to use the same pump every time though).
No vent work done.
40X40 said:
The vehicles are not perhaps as similar as you think, IE, manual vs auto is a big difference.
I was told that if i drove the automatic in manual mode and drove it "by the book" I would be close to a manual tranny MPG.
I'm just trying to figure out what "by the book" means.
 

40X40

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Sorry Stefanne3,

No 59 MPG for your car is not likely.

The route you take has a lot to do with mileage, you could put a couple of more pounds of air in your tires. Top your tank off to the same spot each time, when you are dealing with our numbers, it can make a respectable difference, (do a math example and just change the fuel used by .3 gallons)

Don't expect to break a world record for mileage on a commute.<grin>

Gotta go to work.

Good luck!

Bill
 

BEEnTDI

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40X40 said:
Don't expect to break a world record for mileage on a commute.<grin>
Oh I'm with you on that one brother. I'm thiking 45.5 MPG in the city is good too.

I'm just thinking though ... if 45.5 is in the city, could i get close to 58-59 on a looong trip (say ... 600 miles or so) without stopping - flat almost all the way thorugh? And how?

But still ... how do these guys report 55 and over ... I mean are they driving 40MPH? or what.


ok - so .3 gallon differece

455 miles - 10 gallons - 45.5 MPG
455 miles - 9.7 gallons - 46.9 MPG

That's 1.5 MPG more ... and while that's not a small difference, it's not big enough to account for the ... 15 mpg more between 45.5 and 55 and over.


I would love to be able to communicate as clearly as possible what i'm after.
Hopefully in time we'll nail it.
 

bgarfield

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Mount Airy, MD
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2009 Jetta TDI
I think you need to get on the highway, set cruise for 65mph and avoid ever touching the brakes.

Everyone's numbers are going to be skewed a little because the description of exactly how people get it is far from exact. For example, you could say that you did X amount of miles from a tank (or mpg) and it was "all highway". But then you have to ask "how many stints did it take". If one person gets on the highway with a fresh tank and doesn't stop until the tank is empty, that's probably going to be ideal. However, if another person says "all highway" but they've reached their destination and then started over again 7 times to empty the tank, it's a big difference. Each time the motor has to warm up, getting much less mpg in the process, even on the highway.

Here's another example:
If I was to describe my commute as the same as yours based on hills, highway, and stop-and-go, yet mine commute is 100 miles (vs. your 20), I'm going to get much better mileage than you.

When I'm driving in a traffic light area (city or otherwise), I can manage to almost NEVER use the brakes. I just leave a lot of distance to the person in front of me and never come to a complete stop. Have you tried that? Now apply that to the highway traffic as well. Don't use the brakes, when you do...you've wasted fuel.

Just some thoughts.

Brian
 

BEEnTDI

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I actually do everything you've described already-including the brake usage. And I agree also with your thoughts.

The number of times the engine has to warm up is definitely a factor in the overall fuel economy.

I actually set the cruise at 55 mph and let the car do it's thing - and i drive it like a granny all the time.

I do understand that every once in a while a good romp is needed to get the gunk that accumulates out.


I have the PSI set to 33F/42R because the label says that ... and i figured the manufacturer knows best. Even though it seemed a bit low on the front where the engine is.


Even after hours of reading .. i still don't know what to do:
When a hill comes around and i have the cruise set?
On a flat surface, what's the ideal way of getting up to speed?
What are the shifting points, etc?
 

brucebanes

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45 MPG in an automatic 'Stock' is preety good in my opinion. I think a lot of people lie or miscalculate that post impressive numbers. Ive tried and the most I got was 700 miles on a tank that did not have the vent removed on a 14.5 gallon tank thats 48 miles, 43 MPG on a 16 gallon vented tank. I have talked to people pushing 60MPG by removing emissions equipment, bigger nozzles cutting the engine off when drving down hills and drafting 2 inches behind a truck and running no Air/Heater/radio.

I dont think that extra 12mpg is worth this risk to your car or your life. Drive with Cruise control on enjoy the radio and make sure your intakes are clean, your using synthetic oil and enjoy the ride. It is what it is. Go to one of these Hypermiler meetings sometime when you hear these geeks bragging about their MPG. Get a life DUDE.. and I think many of them are lying just to have the others pat them on a back and be like 'Dude Awesome' your my hero.

If you really want to save fuel ride a bike or turn WVO into BioDiesel.
 

Concat

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2005 Jetta GLS TDi
Sometimes I wonder if those 60 MPG claims are the result of inconsistant fuel ups. Unless you can average around 60 MPG, I tend to lean towards "anomoly."

That being said, my MPG is abysmal. I too have an 05, and I get below 40 MPG in the city. Highway I get like 42 :(

I am due for an oil change + all filters. At that time I will ask them to check to see if any brakes are dragging. I realize winter diesel and colder temperatures will affect my MPG, but is there anythign else that I should ask the shop to check or do?
 

BEEnTDI

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My first thought to your comment was - finally someone that talks some sense! You go boy! And I agree ...

Maybe I'm underestimating these guys, but ... why on earth would anyone lie about something that doesn't really bring them anything other than bragging rights. If this is indeed true then I guess some people are really just that vain.

Hey brucebanes - me ask you some ...


How would you explain this guy (gdr703) - check out his initial post that seems quite extensive and descriptive:
http://forums.tdiclub.com/showthread.php?t=123503

I mean - who spends that much time to write this stuff up and then lie about their mileage. - 59MPG!!! (look at the end of the first post)

And if indeed that is accurate - is that flat road driving? City driving, or highway? Is that the MOST he got or average?

I just can't seem to get the idea behind the MPG difference
 

BEEnTDI

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Concat said:
Sometimes I wonder if those 60 MPG claims are the result of inconsistant fuel ups. Unless you can average around 60 MPG, I tend to lean towards "anomoly."

That being said, my MPG is abysmal. I too have an 05, and I get below 40 MPG in the city. Highway I get like 42 :(
See - i would say that your MPG is not even that high off the mark. The difference between 45.5 and 40 in the city is possibly explainable by ... cruising speed, the way you accelerate, and so on.

Then again i read some posts on here that say ... if you drive 90 MPH the fuel economy is only slightly decreased. So maybe speed is not that much a factor, but i doubt that highly.


I would say try to shift not higher than 2200 RPMs and use the engine between 1300 and 2200. Most of the time though it should be in the middle of those 2 as much as possible.

That's what i think at least.



I'll tell you some interesting though:
If i drive it in manual mode, i can shift whenver i want to.

As soon as i put in auto mode, the computer would shift up from where i thought it should be. The link i posted earlier and many others seems to say that you should always use the highest gear possible, without going below 1300 RPMs.



I drove a 4 cyl 1.9 turbo 240hp engine before. So i'm use to going high on the RPMs to make up for the lack of torque. Diesels are different though and i'm slowly seeing that.
 

FlyTDI Guy

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A couple other things to keep in mind, every car is different. My first TDI consistently got 46-48 mpg without undue care in driving. My current car get more like 42 mpg. My daily commute is about 85% freeway, 15% city. Both engines set up identical and I've never have figured out exactly why.

The other thing is some of the numbers here, I take with a grain of salt. If, indeed, some folks can average over 50 mpg consistently, I wouldn't want to drive my car in such a manner to achieve that. My only forays into the +50 mpg area have been 100% freeway trips and moderate speeds (60-65 mph) and, even then, not 100% of the time. If you're getting 45 mpg city w/an automatic, I'd say your doing very well. Most report high 30's to low 40's w/the tiptronic. Drive more, worry less... :D
 

BEEnTDI

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FlyTDI Guy said:
Drive more, worry less... :D
I like that :)

I just figured ... if there's 10-15 mpg more to be had ... I should at least inquire about it. Feel me?

After all the only price is couple mins of my time.
Thanks for the confirmation though.
 

Concat

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stefanne3 said:
See - i would say that your MPG is not even that high off the mark. The difference between 45.5 and 40 in the city is possibly explainable by ... cruising speed, the way you accelerate, and so on.

Then again i read some posts on here that say ... if you drive 90 MPH the fuel economy is only slightly decreased. So maybe speed is not that much a factor, but i doubt that highly.


I would say try to shift not higher than 2200 RPMs and use the engine between 1300 and 2200. Most of the time though it should be in the middle of those 2 as much as possible.

That's what i think at least.
Well even driving with fuel efficiency in mind (ie. coasting, keeping rpms low) it does not give me an appreciable difference.

I mean, 32 MPG in the city and 40 on the highway on an 05 just doesn't seem quite right to me. Something has to be bogging me down.

I would be delighted, nay, ecstatic to get 40 mpg in the city!

And yes, I drive a manual.

I was just hoping someone could give me more things to look over. But every time I see this question asked, the responses are always in regards to driving style. I shouldn't have to draft 3 feet behind semi's on the highway, or turn off the engine when going down hill to get good MPG!
 

shizzler

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Or, you can aero mod your vehicle such that less power is required to travel at the same rate of speed. My commute is all highway and I rarely keep my speed under 70 mph. Even with multiple cold starts my tanks avg 50mpg.

Pure highway with no attention to hyper-miling I hit 55mpg consecutively. I have no interest in being an obstacle on the road ways, nor the patience to drive and accelerate pathetically slow. But sub 50mpg was not acceptable for me so some mods were in order.

OP, 45 mpg with an auto in any sort of mixed driving is fantastic mileage. Don't be swayed by the 60+ claims on this site as every single one of them involves either perfectly ideal driving conditions or dangerously slow driving.
 

Turbospool

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FlyTDI Guy said:
A couple other things to keep in mind, every car is different. My first TDI consistently got 46-48 mpg without undue care in driving. My current car get more like 42 mpg. My daily commute is about 85% freeway, 15% city. Both engines set up identical and I've never have figured out exactly why.

The other thing is some of the numbers here, I take with a grain of salt. If, indeed, some folks can average over 50 mpg consistently, I wouldn't want to drive my car in such a manner to achieve that. My only forays into the +50 mpg area have been 100% freeway trips and moderate speeds (60-65 mph) and, even then, not 100% of the time. If you're getting 45 mpg city w/an automatic, I'd say your doing very well. Most report high 30's to low 40's w/the tiptronic. Drive more, worry less... :D
What in the world is gained by lying about your MPG's ...... absolutely nothing! I agree with part of your post ... thats the part on getting 45 mpg being good for an automatic . But the part about averaging over 50 mpg. and not wanting to drive a car like that is bunk! I have a blast driving mine and the only time I see less than 50 is heading into a stiff head wind at 75 mph. Car's are different, manual tranny + well pumped tires+ scanguage+ (a few mods, these are less significant) all contribute to Power/fun , and great MPG. I can't figure you guys out! :D
 

ruking

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FlyTDI Guy said:
A couple other things to keep in mind, every car is different. My first TDI consistently got 46-48 mpg without undue care in driving. My current car get more like 42 mpg. My daily commute is about 85% freeway, 15% city. Both engines set up identical and I've never have figured out exactly why.

The other thing is some of the numbers here, I take with a grain of salt. If, indeed, some folks can average over 50 mpg consistently, I wouldn't want to drive my car in such a manner to achieve that. My only forays into the +50 mpg area have been 100% freeway trips and moderate speeds (60-65 mph) and, even then, not 100% of the time. If you're getting 45 mpg city w/an automatic, I'd say your doing very well. Most report high 30's to low 40's w/the tiptronic. Drive more, worry less... :D
For sure, whatever models are made to fall within a statistical variation. These actual figures seems to literally be better kept than state secrets. The actual variations are what we experience.

So for example, while I think I have a "statistically" average 2003 TDI 5 spd, it gets the following ranges:

48-52 mpg daily commute,

49/50 mpg consistently. (5 spd manual, so 45 is good) The next frontier is to get 45 mpg without the emphasis on mpg?

I have gotten a range of 44 to 62 mpg.

At a steady 75 mph with bursts to 80-85 mph, it has gotten 59 mpg.

It has gotten 48 mph (48.26) consistently @ xx.xxx mph (584 miles over 6.25 hours, with a 12.1 gal fill )

So indeed once you know and feel the difference in TDI's vs gassers, drive more worry less !!
 
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Ian F

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Croydon, PA
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I've wondered about these mileage nubmers as well... My car has averaged in the mid-upper 40's since I bought it new... 203K miles ago... increasing tire pressure helps a little - I run 40+ F& R, but at most only netted an increase of 2-3 mpg on average you have gotta check tire pressure often, and when you are leaving the house at 5am, it tends to be the last thing on my mind...

IMHO, shizzler either lucked into some kind of miracle car or the gallons that go into his car are somehow bigger than the gallons my car gets... I would not consider that to be normal without extensive use of hyper-miling techniques - which I tend to do by default when driving the Dodge (~21 mpg), but not when driving the TDI - just too much like an annoying work for not enough benefit... a TDI is annoying enough to drive under normal conditions...
 

BEEnTDI

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Concat said:
I mean, 32 MPG in the city and 40 on the highway on an 05 just doesn't seem quite right to me. Something has to be bogging me down.

I would be delighted, nay, ecstatic to get 40 mpg in the city!
Ok - so you're getting 40 on highway driving? and only 32 in the city? Something's definitely going on ... I agree.

I mean unless you're romping on it all the time, there's no way you can account for that big of a difference with just driving style. 32 mpg in the city, that's ... gasser territory.

You carrying a lot of stuff in your car that you don't need. Weight generally kills acceleration. But then again - even with extra weight for a diesel it shouldn't make that big of a difference.


Have you ever gotten more than 32 in the city? Have you had the car since it was new? How long have you had it for? Trying to figure out if anything happened to cause the low mpg
 

Concat

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Only had it a few months. Never carry anything worth mentioning... so weight's not an issue.

I don't drive like a madman. It's winter after all.

I'm at a loss to explain it myself. But nothing suggests there's anything wrong with her. She starts up nicely, even in very cold temperatures. She idles great, never seen limp mode... acceleration is great... I dont get it.

I'm waiting to get the filters changed before I really get worried. And check to see if the brakes are dragging. But that's all I know. Should I get the timing checked too? Anything else?
 

robnitro

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I think driving conditions and fuel matter most. A year after I got my car, my friends and I drove down to BMW Sharkfest in Alabama. Doing 10-15 mph above the speed limit, driving in a high speed/ twisty mountain run along with the BMW's, and driving back.... I got 52 mpg on that tank. The next tank was around 52, and the one after that was 50!

I was shocked, because I never got above 47 before that, even going AT the speed limit. I think the fuel had a lot to do with it, because the mileage started trailing off the more north I got (even though it was summer).

I got 27-29 mpg towing a fully loaded 5x8x5 uhaul trailer cross country, doing 10 above (some areas super hilly w speed limits of 70 or 75!- shifting down to 4th on long hills to keep EGT's down).

Nowadays, in mostly city driving in the NYC boroughs, I get in the low 30s mpg. The stop signs, red lights, and traffic are so condensed that the official city rating conditions look more like our highway conditions, LOL. (Just for comparison to gasser territory, my 95' Civic got 32 hwy, and was rated 29/32. In the same conditions here, I got LOW 20's!)

So, it all depends on the conditions... Driving fast down south, I got consistent 52 mpg, and up here I get "only" 47-49 mpg on the SLOWER highways?
 

BEEnTDI

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shizzler said:
Or, you can aero mod your vehicle such that less power is required to travel at the same rate of speed. My commute is all highway and I rarely keep my speed under 70 mph. Even with multiple cold starts my tanks avg 50mpg.
Pure highway with no attention to hyper-miling I hit 55mpg consecutively.
How can that be ... you're driving 70mph and you're getting 55? I drive 55 and i get 45 MPG.

I find it hard to believe that auto to manual would be that big of a difference - especially given the different speeds which would favor the automatic gearbox.


shizzler said:
OP, 45 mpg with an auto in any sort of mixed driving is fantastic mileage. Don't be swayed by the 60+ claims on this site as every single one of them involves either perfectly ideal driving conditions or dangerously slow driving.
So then how can 45 be fantastic mileage if you're getting 55 consistent?

Why couldn't i aspire to have that? :)
 

FlyTDI Guy

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There is a significant difference in economy between a the manual and tiptronic... sorry. The EPA stickers for your year even reflect that. Don't set yourself up for disappointment by expecting manual transmission fuel economy. Not gonna happen. That being said, I repeat, you're doing quite well for an auto...
 

BEEnTDI

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So then - what do you think would the most that i could get - highway driving, ideal conditions (constant speed, etc)
 
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