MPG vs Transmission...???

[AlmondFarmer]

I'm getting ready to make a purchase of a new '12 Passat TDI. I am making a change from a Jetta to the Passat. It doesn't seem to much more money for more room and .... (educate me if I'm mistaken or missing something)....

The main question is which transmission to buy??? Am I correct in reading that the manual gets about 43mpg highway and the DSG gets 40mpg? What are the "real world" results? What are you getting with xxxxx transmission?

FYI, I plan on using the vehicle about 30% city and 70%highway...

Lastly, on a side note, I have been looking at inventories of various dealerships. There seems to be many variations and extreme price differences in those configurations, i.e. $27K to $34k. On those inventory pages, there doesn't seem to be much difference in what those car have as options. Should I be careful about any particular option? I don't want NAV, but what should I look at when shopping?

Thanks for your insight.

 

[WVU TDI]

The manual will get better mileage, and should be much cheaper to maintain over the life of the car. Only real downside to the manual is that you can only get it in the most basic Passats. Want a sunroof? Automatic only. Want the fender audio system? Automatic only.

 

[Daily Diesel]

WVU is spot on. I have the manual trans 36 city, 48 highway.... About 44 with a 70/30 mix. Options I had to give up for the stick: nav, sun roof, premium audio. Do I care? No. Space, comfort, and fuel economy are best inclass for me.

 

[740GLE]

The car's really too new to judge what the car can pull down on the high end of MPG or average out after the engines broken in (20,000-50,000 miles) but from history on a 2.0L CRs in the jetta, MPG can't be beat with a 6spd Manual on the highway. If you drive it right and possibly baby it on the highway, you should be able to eak out 45-47mpg if you keep your speeds low enough and drive constantly.

For me the biggest thing that kills my MPG is driving any distances under 20 miles, there's just not enough time for the engine/emissions crap to get up to temp to work their best. Before 20 miles MFD seems to be around 40 mpg, after 20 miles the MFD just keeps going up until it reaches around 47-52mpg.

 

[wolfsburg_de]

Even though I would have loved to have a sunroof, the TDI isn't technically the base stripped model, which would be the S. The SE has alloys, pleather (which in VW's mind is an upgrade over cloth), power seat, etc. Not as loaded as I'd like (or the Canadians can get with 6MT) but it doesn't feel like a penalty box either. Then again, maybe I just have a touch of Stockholm Syndrome.

 

[TDICT]

Don't let the EPA fool you. Only 1,500 miles so for on my Passat TDI SEL but highway at 70 mpg shows me 46-47 mpg. Better than my 2009 JSW TDI.
Not sure why the highway mileage should be any different from the stick to the DGS. DGS is a direct no slip hook up the same as the manual unless there is a final drive gear ratio difference. DGS has no power loss unlike a conventional automatic with a torque converter.

 

[wolfsburg_de]

I think there is a gearing difference between DSG and 6MT. What does your DSG show for RPM at an indicated 70 mph in 6th? In my 6MT, it's about 1950 rpm.

 

[740GLE]

Wait, on the highway you were getting 70MPG? but the MFD only stated you were getting 47MPG? wow mark that up with the fuel gauge issue!!!

Also trip mileage on the MFD doesn't mean anything, post you got 850 miles on one tank, filled brimming tank to filled brimming tank with a DSG then we'll all eat crow.

DSG's in the past have had to spin faster than the 6Spds at 70 mph.

 

[TDICT]

Wait, on the highway you were getting 70MPG? but the MFD only stated you were getting 47MPG? wow mark that up with the fuel gauge issue!!!

Also trip mileage on the MFD doesn't mean anything, post you got 850 miles on one tank, filled brimming tank to filled brimming tank with a DSG then we'll all eat crow.

DSG's in the past have had to spin faster than the 6Spds at 70 mph.

Yea...Typo on the 70mpg as you know it should be 70mph!
Don't say the MFD display means nothing. I put on 82k miles on my 2009 JSW TDI and found the MFD to be accurate when ever I checked it against gallons used divided by miles driven.
Do you really think I am going to wait until I have 850 miles to re-fuel. I have been driving diesels for years and know that fuel is not always at the next exit. Hey, you can eat what ever kind of bird you want but I'm not walking to the station holding a fuel can!

 

[skinnyb]

I think there is a gearing difference between DSG and 6MT. What does your DSG show for RPM at an indicated 70 mph in 6th? In my 6MT, it's about 1950 rpm.

My DSG is at 2200 with indicated 70 MPH. I thought it was because of the larger car as my MKV said around 2000 at the same speed.


Sent from my iPhone using Tapatalk

 

[TomB]

Anyone know why the transmissions would be geared differently considering the DSG is effectively a manual transmission. Maybe perception of being quicker more responsive by having a higher overall ratio? Maybe they think Americans want that in an "automatic" with all the extras?

2200 RPM versus 1950 at 11% so that would equal the 4 MPG difference.

What size tires are on the 6MT and the DSG?

 

[oxford_guy]

I wonder if the cost of DSG maintenance is higher than any MPG difference.

What size tires are on the 6MT and the DSG?

17" manual
17" DSG SE/roof
18" DSG SE/nav
18" DSG SEL

 

[wolfsburg_de]

2200 RPM versus 1950 at 11% so that would equal the 4 MPG difference.

What size tires are on the 6MT and the DSG?

My 6MT SE has 215/55-17 just like a DSG TDI SE, or a 2.5 6AT SE for that matter.

 

[TomB]

I think there is a gearing difference between DSG and 6MT. What does your DSG show for RPM at an indicated 70 mph in 6th? In my 6MT, it's about 1950 rpm.

So I looked up the publish specs and the effective top gear engine rpm to tire rpm is 2.10 for the manual and 2.31 for the auto so 10% diff.

Now if we look at the tires, the rotations per mile of Continental is 793 for both of the sizes. For Hanook the 18" are 789 revs per mile and Hanook is the brand we are seeing on the SEL's.

It appears at 1942 rpms on the manual it is 70 MPH and 2126 rpms on the auto is 70 MPH, so about a 9.4% difference. Pretty good observation.

I wonder if they did this because of rotational torque required to get the larger tires moving initially. Raising the final drive ratio will give you more torque.

That was the whole point of the granny 1st gear in the 2005 to improve MPG.

 

[Ski in NC]

Interesting that the Passats seem to be getting as good or better mpg than the jettas. Maybe due to pee-tank NOx control?? Nice, anyhow!!

And to the OP regarding which tranny: Get the MANUAL!!

(ok, being a little flippant there, but if you and any other drivers are comfortable with a manual in your duty cycle, that is my suggestion. Diesels like manuals and so will you!!)

 

[wolfsburg_de]

In Canada, you can get 18" tires with a manual and there are plenty of DSG SE's with 17" tires (and some 16" in Canada) so I doubt the wheel size choices were picked based on transmission. It seems like with an automatic transmission, you could get away with an even taller 6th gear than a manual since it will just downshift if you need more oomph, say climbing a grade or passing. With a manual, you risk annoying the operator if he needs to do that for every little rise in elevation. My wife has a Pontiac Vibe 5MT that's like that. It has very little peak torque (125 lb-ft) and what it has is at high RPM (4400). As much as I like driving manuals, it bugs me to have to downshift to 4th (or 3rd!) to maintain speed on interstates.

 

[thegradas]

In Canada, the TDI Trendline+ manual transmission comes with 16" alloy wheels.
Due to the high torque, you don't feel the need to downshift when passing/accelerating with a diesel.
I agree, my previous 5MT Focus displayed similar behaviour as your wife's Vibe.

In Canada, you can get 18" tires with a manual and there are plenty of DSG SE's with 17" tires (and some 16" in Canada) so I doubt the wheel size choices were picked based on transmission. It seems like with an automatic transmission, you could get away with an even taller 6th gear than a manual since it will just downshift if you need more oomph, say climbing a grade or passing. With a manual, you risk annoying the operator if he needs to do that for every little rise in elevation. My wife has a Pontiac Vibe 5MT that's like that. It has very little peak torque (125 lb-ft) and what it has is at high RPM (4400). As much as I like driving manuals, it bugs me to have to downshift to 4th (or 3rd!) to maintain speed on interstates.

 

[AlmondFarmer]

Thanks for all the insight. I'm leaning toward the MT, but....

I don't trust the trip computers too much. I believe they are more of an estimate rather than actual mpg. I trust the 'ol fashion measurement of full tank to full tank. Yeah, I know, there's foaming issues, but I think if you're careful, that can taken care of. Therefore, What is your actual mpg on your new DSG's and MT's? (EPA says that they should be nearly the same)

Lastly, are there limitations for putting snow chains (cable-style) on these Passats? I know, kind of dumb, but here in CA, to go to the Sierra's, Highway Patrol requires use on snowy days.

 

[WVU TDI]

Over my car's 30k mile lifetime, I've tracked the mileage through fuelly as well as documented the MFD's average mpg reading. On average, my mfd is less than 1% optimistic. Seriously.

 

[TomB]

Over my car's 30k mile lifetime, I've tracked the mileage through fuelly as well as documented the MFD's average mpg reading. On average, my mfd is less than 1% optimistic. Seriously.

Mine varies between 3-10%. I have tracked over 120K miles on an excel spreadsheet on both the Passats and the variance is the same.

What brand/size tires do you have? I had the Michellins in the 17" the whole time. Switching to the 16" for winter brought it more in line. It is slightly better now with the Yokohama Envigor 17" with only 2-7% differences.

 

[TDICT]

There has been a lot of speculation as to mileage, RPM @70mph and the fuel gauge readings.

Sorry for the poor quality photos, shot with cell phone.

2,200 RPM is 70 mph (this is on cruise control. MFD shows 70 mph although the needle shows it slightly higher. I fueled up and had 22.1 miles on this tank. You can see the fuel gauge still shows full. Fuel burn at 70mph is 47.3 mpg. This fuel average was over at least 20 miles highway mileage. Air temp was 56 degrees.
For what it's worth my mixed mileage is always north of 40 mpg. Not sure about the accuracy of older VW's but my 2009 TDI JSW the MFD was dead on over the course of the 82k miles I put on it.

2012 Passat TDI SEL DGS now with 2,000 miles.

 

[WVU TDI]

Mine varies between 3-10%. I have tracked over 120K miles on an excel spreadsheet on both the Passats and the variance is the same.

What brand/size tires do you have? I had the Michellins in the 17" the whole time. Switching to the 16" for winter brought it more in line. It is slightly better now with the Yokohama Envigor 17" with only 2-7% differences.

The factory 225/45/17 Continental ProContacts. The 09+ cars' MFDs are much better than any of the earlier models.

 

[Kchorro]

My TDI SEL came with Bridestone Turanza. 235/45/R18
They are great quiet tires.
Car build date 8/2011

 

[WVU TDI]

My TDI SEL came with Bridestone Turanza. 235/45/R18
They are great quiet tires.
Car build date 8/2011

Turanza are nice, quiet and comfy like you said. Unfortauntely, I've never gotten more than 25k miles out of a set, no matter the vehicle.

 

[740GLE]

Have you tried the turanza serenities? looks like they are suposed to compeat with Mich's for a nice grand touring tire that should last quite a while.

BTW my comments I made earlier about stretching the mileage out for the entire tank and making sure the tank is actually full to the top is on my MFD, I've seen varrying numbers on each "trip" of a tank, some ranging from 56mpg down to 32mpg, yet hand calculating with each full tank, I get around 43-48mpg average.

I guess if your resetting the "trip 2" MFD reading each time you fill up then it'd be a good judge of your mileage.

 

[WVU TDI]

I guess if your resetting the "trip 2" MFD reading each time you fill up then it'd be a good judge of your mileage.

That's how I do it.

In fact, that's really the only way to do it.

 

[TomB]

That's how I do it.

In fact, that's really the only way to do it.

X2.

Use this as the reference to compare to versus the actual miles/gallon calculation.

 

[MyAvocation]

I don't trust the trip computers too much. I believe they are more of an estimate rather than actual mpg. I trust the 'ol fashion measurement of full tank to full tank.

If you have a MFD, there's a good chance it can be calibrated with VCDS. It's possible on the mk5 models.

You'll find the How To in the mk5 forum or at Ross-Tech. From what I recall it's calibrated under Instruments|Adaptation|Channel 3. You simply calculate the delta between actual and displayed averaged across numerous tankfuls. Then increase/decrease the setting in increments of whole %. Since calibrated, mine is never +/- .5 MPG.

 

[740GLE]

That's how I do it.

In fact, that's really the only way to do it.

What's wrong with a paper and pen? and filling up 100% each time? to me that's the only acurate way to know the MPGs, even though the MFD is pretty close.

 

[WVU TDI]

What's wrong with a paper and pen? and filling up 100% each time? to me that's the only acurate way to know the MPGs, even though the MFD is pretty close.

I meant the only way to get mileage info from the MFD. I track my fuel with "pen and paper" through fuelly, and I also note the MFD reading on each tank, as well as the average speed reported by the MFD.

The fuelly link for my '01 doesn't show this, 1) because my dad's driving it now and barely tracks the fuel in anyway, 2) it doesn't have an MFD or scangauge or anything.