OT: Suby fuel consumption

[velotel]

My wife drove the Outback from our house in the mountains near Grenoble down to Hyères on the Med coast, averaged 49mpg going down. By the time she got back to the house a week later, the average had dropped to 44. That included town driving, traffic jams, highway, small mountain roads. Not bad for a big car with permanent 4x4 eh! Seriously sweet car.

[dekindy]

Very skeptical of those numbers.

[velotel]

It's a diesel, you don't have them over there. Awesome motor.

[oldpotatoe]

It's a diesel, you don't have them over there. Awesome motor.

Yup...diesel is a great idea..diesel here is only about $.05 more than gas and I get around 40 mpg all the time, road trip to Wisconsin, about 50 MPG....Jetta TDI.

[dekindy]

It's a diesel, you don't have them over there. Awesome motor.

Well, you did not say that. I am considering a Volkswagen diesel for next car. A couple that I bicycle ride have a sedan and wagon diesel and swear by them. Don't some diesels get as good or better mileage in town as on the highway?

Savings adjusted for higher cost of diesel; or is that different over there also?

I wish Subaru and Ford would offer diesels in the USA.

[skijoring]

Yup...diesel is a great idea..diesel here is only about $.05 more than gas and I get around 40 mpg all the time, road trip to Wisconsin, about 50 MPG....Jetta TDI.

I'm curious what the first service and additional costs are associated with diesels vs. a petrol car that gets 35-40 mpg. My research and math indicates it kind of blows the value proposition out of the water.

[Mr. Pink]

It's a diesel, you don't have them over there. Awesome motor.

Damn.

I have read that there's a Mini diesel over there that gets almost 60mph, and at the same time, has some serious performance numbers, like 0-60 in something like 6 sec.

America goes all gaga about a $90,000 electric Tesla that will only go 200 miles or so between charges and only the 1% can afford (because it's a toy, after all. A status object), and the Euros actually get high mileage cars the average schmoe can buy.

[oldpotatoe]

I'm curious what the first service and additional costs are associated with diesels vs. a petrol car that gets 35-40 mpg. My research and math indicates it kind of blows the value proposition out of the water.

Free service for first 3 years, 36,000 miles with the Jetta. Service every 10,000 miles..mainly oil change.

NO mid sized station wagon on gas gets 35-40 MPG, overall mixed driving. Apples to apples, a Jetta gas is 'rated' by various websites at around 30 MPG overall with the diesel about 8 MPG more. I routinely get 38-40 MPG, mixed driving around Boulder/Denver/Broomfield.

But I didn't get it cuz of $, I got it cuz it's a great car to drive..with the very torquey diesel..plus kinda designed to last 'forever'...not gonna need to buy another car...period.

[gavingould]

i got 45mpg avg on two trips between Chicago and Madison WI this past weekend, 75-80mph. Sportwagen TDI. in town, short trips the engine barely gets warmed up, so mileage not great around town, but still mid to high 20s. on the open road it's a beast.

[rwsaunders]

Yup...diesel is a great idea..diesel here is only about $.05 more than gas and I get around 40 mpg all the time, road trip to Wisconsin, about 50 MPG....Jetta TDI.

$0.3-0.4/gallon more than unleaded where I live, or did you mean $0.5? In the early '80's, the cost per gallon of diesel was much lower than gas and the mixed mileage for the diesel Vdubs was also 40/50 mpg. It was a no brainier for me then. When you weigh the total cost of ownership of gas vs diesel vehicle right now, it can go either way depending on your car selection.

I will say though, that the performance of today's Vbud diesel engines far outperform the older ones in terms of power. The mileage has remained the same, which isn't a bad thing either.

[zap]

America goes all gaga about a $90,000 electric Tesla that will only go 200 miles or so between charges and only the 1% can afford (because it's a toy, after all. A status object), and the Euros actually get high mileage cars the average schmoe can buy.

Diesels contribute to the continuing high levels of air pollution in Europe.

http://www.telegraph.co.uk/motoring/news/10862975/Emission-tests-substantially-underestimate-pollution-pumped-out-by-diesels.html

[oldpotatoe]

$0.3-0.4/gallon more than unleaded where I live, or did you mean $0.5? In the early '80's, the cost per gallon of diesel was much lower than gas and the mixed mileage for the diesel Vdubs was also 40/50 mpg. It was a no brainier for me then. When you weigh the total cost of ownership of gas vs diesel vehicle right now, it can go either way depending on your car selection.

I will say though, that the performance of today's Vbud diesel engines far outperform the older ones in terms of power. The mileage has remained the same, which isn't a bad thing either.

5 cents, a nickel more per gallon.

[Netdewt]

Yup...diesel is a great idea..diesel here is only about $.05 more than gas and I get around 40 mpg all the time, road trip to Wisconsin, about 50 MPG....Jetta TDI.

Ours is $0.50-ish more because of state taxes... grr. Still worth it though.

[carpediemracing]

Well, you did not say that. I am considering a Volkswagen diesel for next car. A couple that I bicycle ride have a sedan and wagon diesel and swear by them. Don't some diesels get as good or better mileage in town as on the highway?

Savings adjusted for higher cost of diesel; or is that different over there also?

I wish Subaru and Ford would offer diesels in the USA.

tl;dr - we bought diesel for driving performance as well as the good mileage (the idea of it), but not necessarily for cost savings overall.

As posted in other threads, I'm sure people are tired of it lol, we have a 2010 Jetta Sportswagen (JSW) TDI and a 2012 Golf TDI.

Although fuel mileage was a concern (I felt dumb buying a car that wouldn't get significantly better mileage than the 28-33 mpg I got in my 0-60 in 5.5 seconds car) I also didn't want to lose the torquey fun part about driving. The TDI has an immense amount of torque, 235 ft-lbs, give or take, relative to the 285-290 ft-lbs of my previous car. I actually thought my "fast" car wasn't that fast after driving the Missus's JSW regularly - the fast car only came to life at or above 50 mph (ideally 50-100+ mph) due to its higher HP. I learned once again that HP is simply torque x rpm and that HP really comes into play at speed.

With the TDI we can get up any hill on the highway without getting in the way of others, holding 65-80 mph on long hills while still getting 16-20 mpg according to the "instant mpg" display. I can get rid of lower HP/TQ tailgaters simply by waiting for a hill and accelerating up it at a moderate level.

The best mileage numbers pop up when we're on the quieter backroads - think of ideal cycling roads and that's what I mean. We get 50-55 mpg on such roads, even on round trips. In stop and go it's worse than a hybrid (which typically doesn't even use gas while not moving) - we see in the mid 30s for slower drives or short drives (1 mi commute for the Missus, 2 miles for daycare, 3 miles for town).

We bought a second TDI (my choice) to get both cars on diesel. We have a seemingly long term grocery store + gas station deal in the area, grocery store purchases go towards fuel discounts. With two TDIs, two 5 gal cans, we can go about 1500 miles for the two cars between fill ups. That's about a month, maybe a bit more, and it means that when we finally get fuel we save anywhere from $0.80-1.00 per gallon. A high number might be $1.30-$1.40 - I think our last fill up was $1.30 off per gallon. With diesel at about $3.70/gal that's a substantial savings.

Prior to that we had my fast car (350Z) which was gas and the JSW which was diesel. No such mass purchase savings.

So for us it was a number of things: a high minimum level gas mileage (40 mpg) else I'd be back in 350Z territory; a minimum level of torque (200 ft-lbs?) to give reasonable responsiveness in the 20-70 mph speed range; a minimum level of room - 4 adults and 1 child seat. The Golf worked out.

I initially wanted a second JSW but the Missus told me that if we got a Golf then I could mod it as I wanted after a bit. JSW is a touch less modifiable in terms of parts available.

A thought about good mileage on downhill drives - in my (gasoline) 1988 GTI I saw a displayed 50 mpg when I drove from Limerock to where I then lived near the shoreline. It's 2 hours, all slight downhill, there's almost no highway, so ideal 35-50 mph speeds. I normally got in the 30-33 mpg range.

Driving the same car from Mount Snow down to where the roads leveled out I saw 80 mpg before the roads leveled out. On downhill stuff it's incredible how good mileage I could get. This is on an engine that runs even when you coast - the TDIs we have don't feed fuel into the engine if you have no throttle, it uses the mass of the car to keep the engine and ancillaries turning. If you do a neutral coast the engine has to start using fuel.

[carpediemracing]

Ours is $0.50-ish more because of state taxes... grr. Still worth it though.

Recent gas tax chart. Apparently CT is one of the more expensive. They also have the diesel adjustment. From jalopnik here (http://jalopnik.com/why-gasoline-prices-vary-so-much-from-state-to-state-1631626677).

http://i.kinja-img.com/gawker-media/image/upload/s--ou_TEvN3--/c_fit,fl_progressive,q_80,w_636/oxyr1hoicizmy8nuxqlc.jpg

[thwart]

Diesels contribute to the continuing high levels of air pollution in Europe.

http://www.telegraph.co.uk/motoring/news/10862975/Emission-tests-substantially-underestimate-pollution-pumped-out-by-diesels.html
Pertinent excerpt from that piece:

So what, if most of our driving is in town, should we be driving instead of a diesel? “There’s no easy answer,” says Molden. “Most technologies involve some form of trade-off. Petrol cars emit less NOx but more carbon dioxide, plus they use more fuel. Hybrids can be good in town, but less so on the motorway. Electric vehicles have no exhaust emissions but are expensive to buy and have limited range. The trouble is the official data informing these trade-offs isn’t complete or accurate. That’s why real-world emissions data is so valuable.”
Molden agrees with North’s suggestion that better-managed traffic flow is important in reducing NOx levels, but also points to the development of cleaner diesel engines that offer the low carbon dioxide output of today’s cars but with the promise of dramatically reduced NOx emissions.
“The adoption of Selective Catalytic Reduction (SCR) systems should solve the NOx issue for the next generation of diesel engines,” says Molden. SCRs use substances such as urea to convert NOx into nitrogen and water. Car manufacturers are adopting SCR technology in growing numbers, particularly with the more stringent euro 6 emissions standard coming into force this September.
Peugeot’s BlueHDi engine uses an SCR and is fitted to the new Peugeot 308, 308SW and 508. The company claims that the SCR combined with a particulate filter and the use of an additive allows for a NOx reduction of 90 per cent compared with earlier generations of e-HDi diesels. Mercedes-Benz uses SCR under the BlueTEC label while Vauxhall employs SCR technology for its 1.6-litre diesel in the Astra, Meriva and Zafira Tourer.

AFAIK most, if not all, of the new diesels (including those from VW) will be using this technology.

[David Kirk]

What 'gallon' is used where you live? I've been confused more than once when reading British car magazines and seeing their MPG figures and how different they are to the US figures. I then learned that the Imperial gallon used in England is not the same as the US gallon and this accounts for some of the difference between the two countries MPG ratings.

What is 'gallon' is used there?

dave

[Mark McM]

Be careful when you compare figures for diesel vs. gasoline, particularly if you try to compare by volume (gallon), because diesel packs in more (both good and bad) per gallon than gasoline. Diesel is denser (heavier), contains more energy, takes more petroleum to produce, and generates more CO2 per gallon than gasoline. Roughly speaking, a gallon of diesel contains about 10% more (of everything) than a gallon of gasoline.

[Netdewt]

Be careful when you compare figures for diesel vs. gasoline, particularly if you try to compare by volume (gallon), because diesel packs in more (both good and bad) per gallon than gasoline. Diesel is denser (heavier), contains more energy, takes more petroleum to produce, and generates more CO2 per gallon than gasoline. Roughly speaking, a gallon of diesel contains about 10% more (of everything) than a gallon of gasoline.

Isn't it less CO2?
http://news.stanford.edu/pr/02/jacobsonJGR1023.html
http://news.wyotech.edu/post/2012/03/8-advantages-of-diesel-engines/#.VCLpNUuFag9

The VW diesels now have a diesel particulate filter to keep the soot out of the air.

Also, I have read that diesel is easier to refine.
http://www.nacsonline.com/YourBusiness/FuelsReports/GasPrices_2013/Pages/Why-Diesel-Costs-More-Than-Gasoline.aspx

[gavingould]

emissions stds are quite different in US and EU, as far as i know (which isn't all that far.)
i believe for diesel passenger cars they are tougher in the US, which is a reason diesels are not the bargain trim-level cars they are in Europe. more emissions equipment required which makes them more pricey from the get-go.

we went with the diesel because it is efficient for the majority of driving we do (highway) had the creature comforts and space we wanted, plus torque (mainly my request)

i'd actually love an AWD version with about 3 inches more ground clearance. when the snow gets deep, it's mostly lack of clearance that causes problems around here and in the boonies of Iowa where the in-laws are. if the cost is 4-5mpg i could live with that.

[p nut]

[I]So what, if most of our driving is in town, should we be driving instead of a diesel?

Ride your bike!! :)


I'm jealous of those figures. Our Outback gets 32MPG on the freeway, but mixed is around 27MPG. We love it, though, especially in winter.

[Ken Robb]

My friend owns a driving school. He has a couple Jetta TDI sedans with automatics in addition to a mix of Japanese compacts. The transmission in a Jetta died at 103,000 miles----3,000 out of warranty. Because he had done the recommended (rather expensive) service on the transmission VW shared the cost ($7,000) of a new transmission. That transmission failed 70,000 miles later and VW said: tough luck! The service manager at his dealership convinced VW to pay for some of this new repair cost because having these cars used training new drivers was good PR for VW.

The moral to this story, I guess, is that an owner of a car with the dual clutch automatic should be sure to have the tranny serviced and keep a close eye on its behavior from 70,000 miles on. Anyone considering buying a used one should make sure the service was done and/or get an extended warranty.

One of the new cars I have been considering is a GTI with this transmission because it works really well but my pal's experience gives me pause. OTOH I'm not likely to drive 70,000 miles in any one car ever again. :)

[gavingould]

agree, the servicing of the DSG trans is not to be taken lightly. the thing'll probably rust apart before i can get it to 100k miles, 2 years in and just crossed 18000mi. we rarely drive to work.

[benb]

Just for a more apples to apples comparison my non diesel 2.5L Outback has never hit 30mpg for an entire tank of gas. (rated 24/30/26)

It pretty much does what the sticker says we just have tons of traffic which knocks everything down a notch. But it's not going to get 40mpg unless you drop it out of a plane with the engine off!

[velotel]

What 'gallon' is used where you live? I've been confused more than once when reading British car magazines and seeing their MPG figures and how different they are to the US figures. I then learned that the Imperial gallon used in England is not the same as the US gallon and this accounts for some of the difference between the two countries MPG ratings.

What is 'gallon' is used there?

dave
My numbers are american gallons.

[velotel]

Just for a more apples to apples comparison my non diesel 2.5L Outback has never hit 30mpg for an entire tank of gas. (rated 24/30/26)

It pretty much does what the sticker says we just have tons of traffic which knocks everything down a notch. But it's not going to get 40mpg unless you drop it out of a plane with the engine off!
Now that gave me a great laugh. Especially the 'with the engine off' comment. Et voilà why we have a diesel Sub.

[witcombusa]

Wait till you have to replace the HPFP or the exhaust DPF, then you'll see what your cost per mile is :eek:

[David Kirk]

My numbers are american gallons.

cool - just out of curiosity is that the standard there or is is sold by the liter?


dave

[p nut]

... Et voilà why we have a diesel Sub.

Ok, we get it, we get all the crappy cars here in the US. Stop rubbing it in our faces.

:p

[velotel]

cool - just out of curiosity is that the standard there or is is sold by the liter?


dave
All metric here, sold by the litre, consumption is measured by how many litres per 100 km. In other words she got 4,8L/100km

[verticaldoug]

Isn't it less CO2?
http://news.stanford.edu/pr/02/jacobsonJGR1023.html
http://news.wyotech.edu/post/2012/03/8-advantages-of-diesel-engines/#.VCLpNUuFag9

The VW diesels now have a diesel particulate filter to keep the soot out of the air.

Also, I have read that diesel is easier to refine.
http://www.nacsonline.com/YourBusiness/FuelsReports/GasPrices_2013/Pages/Why-Diesel-Costs-More-Than-Gasoline.aspx

This argument is bit like saying by throwing a deck chair off the Titanic, we can keep it from sinking.

Whether a gas or diesel, the production and use of vehicle is a very pollutive process. The manufacturing carbon footprint of a car is probably equal to the carbon you'll produce over the lifetime of driving the car. If you are not driving incredible distances per year, the longer you keep your car the better.

From thermal efficiency, because a diesel engine runs at a higher compression ratio, it should be more efficient than a gas engine. Probably 40% vs 30%.

The craziness is if you stop drinking bottled water, you will probably lower your carbon footprint by a larger amount than getting a better mileage car.
(it's not as insane as it sounds.)

D

[velotel]

Wait till you have to replace the HPFP or the exhaust DPF, then you'll see what your cost per mile is :eek:
You're always so positive. Or at least it seems that way to me. In addition I never said anything about the running costs. Just simply impressed by the fuel consumption she did, nothing more than that.
Cheers

[oldpotatoe]

Wait till you have to replace the HPFP or the exhaust DPF, then you'll see what your cost per mile is :eek:

Or transaxle in a Subaru or a fuel pump for a Mercedes or...........

Called ownership tax and I read that the HPFP failure is in about 1% of the VW diesels and more than a few because the moron put gas in it.

If ya think VW/Audi diesel is a bad idea.....don't buy one.

[Mark McM]

[QUOTE=Netdewt;1627128]Isn't it less CO2?
http://news.stanford.edu/pr/02/jacobsonJGR1023.html
http://news.wyotech.edu/post/2012/03/8-advantages-of-diesel-engines/#.VCLpNUuFag9

No, burning diesel fuel produces more CO2 per gallon, simply because it contains more carbon per gallon than gasoline (which is largely why it weighs more, and contains more energy per gallon). Diesel fuel contains about 15% more carbon than gasoline, and about 11% more energy, by volume.

However, diesel engines have fuel efficiency of about 40% more than gasoline engines. So, the net effect is that diesel engines burn far less fuel than gasoline engines, and even at the higher CO2 production per gallon, diesel engines produce less net CO2 - but closer to 15% less, not 40% less.

This is why in terms of the greenhouse gas CO2, you can not compare diesel fuel to gasoline on a volume (per gallon) basis. You need to compare them on a carbon basis.

For more: http://www.eoearth.org/view/article/160424/

[rilz]

+1 glad to see someone post something of substance in this argument :hello:

[QUOTE=Netdewt;1627128]Isn't it less CO2?
http://news.stanford.edu/pr/02/jacobsonJGR1023.html
http://news.wyotech.edu/post/2012/03/8-advantages-of-diesel-engines/#.VCLpNUuFag9

No, burning diesel fuel produces more CO2 per gallon, simply because it contains more carbon per gallon than gasoline (which is largely why it weighs more, and contains more energy per gallon). Diesel fuel contains about 15% more carbon than gasoline, and about 11% more energy, by volume.

However, diesel engines have fuel efficiency of about 40% more than gasoline engines. So, the net effect is that diesel engines burn far less fuel than gasoline engines, and even at the higher CO2 production per gallon, diesel engines produce less net CO2 - but closer to 15% less, not 40% less.

This is why in terms of the greenhouse gas CO2, you can not compare diesel fuel to gasoline on a volume (per gallon) basis. You need to compare them on a carbon basis.

For more: http://www.eoearth.org/view/article/160424/

[Netdewt]

Isn't it less CO2?
http://news.stanford.edu/pr/02/jacobsonJGR1023.html
http://news.wyotech.edu/post/2012/03/8-advantages-of-diesel-engines/#.VCLpNUuFag9

No, burning diesel fuel produces more CO2 per gallon, simply because it contains more carbon per gallon than gasoline (which is largely why it weighs more, and contains more energy per gallon). Diesel fuel contains about 15% more carbon than gasoline, and about 11% more energy, by volume.

However, diesel engines have fuel efficiency of about 40% more than gasoline engines. So, the net effect is that diesel engines burn far less fuel than gasoline engines, and even at the higher CO2 production per gallon, diesel engines produce less net CO2 - but closer to 15% less, not 40% less.

This is why in terms of the greenhouse gas CO2, you can not compare diesel fuel to gasoline on a volume (per gallon) basis. You need to compare them on a carbon basis.

For more: http://www.eoearth.org/view/article/160424/

I get it. But generally, a modern diesel produces less per mile than a modern gasoline car of similar size, yes?

I know it's not much of a difference. Better to go ride your bike.

[Cat3roadracer]

Or transaxle in a Subaru or a fuel pump for a Mercedes or...........

Called ownership tax and I read that the HPFP failure is in about 1% of the VW diesels and more than a few because the moron put gas in it.

If ya think VW/Audi diesel is a bad idea.....don't buy one.


This is interesting. I too own a JSW with the DSG trans. Absolutely love the car. As one would imagine there is a forum just for TDI models, a wealth on information, just as we see here.

People modify these cars with all sorts of crap. Burning kerosene, various sorts of bio, fuel treatments, the list goes on.

If the recommended service interval is followed I see no reason why this car will not last hundreds of thousands of miles. I am just turning 10k, so I am new to the game.

Highly recommended.

[witcombusa]

Or transaxle in a Subaru or a fuel pump for a Mercedes or...........

Called ownership tax and I read that the HPFP failure is in about 1% of the VW diesels and more than a few because the moron put gas in it.

If ya think VW/Audi diesel is a bad idea.....don't buy one.


Just bringing it up because a guy I work with just went through a DPF on his 2010 Jetta TDI.