Cruising speed for best fuel mileage?

[RudyH]

Hello:
can you recommend a good highway cruising speed for best fuel economy with the Sportwagen TDI? 62 has been a sweet spot with my gas car, where its plenty fast, doesn't attract cops, and yields good mileage. I got better mileage at 62 than at 55.

Now I need to find the same sweet spot for the VW.

 

[Pyke]

"Light foot"

Get to the speed you want, have a REALLY NIGHT FOOT, and you will get 50MPG. I did this at 80MPH on my Jetta tDI.

 

[740GLE]

depends if you have the DSG or 6MT.

I get some good results (45-50) at 60-65 constantly. If the weather plays nice I can get the same results at higher speeds around 75.

 

[RudyH]

Thanks, it's DSG.

 

[OldManWinter]

I get amazing mileage at around 75km/h (Less than 4 l/100km), but that's too slow to get anywhere in time.

At 108km/h I get around 4.7-4.9 l/100km.
At 130km/h I only get 7.0-7.2 l/100km.

I'm not sure how that translates to MPG etc.

 

[ruking]

Hello:
can you recommend a good highway cruising speed for best fuel economy with the Sportwagen TDI? 62 has been a sweet spot with my gas car, where its plenty fast, doesn't attract cops, and yields good mileage. I got better mileage at 62 than at 55.

Now I need to find the same sweet spot for the VW.

The first thing to do is to look at your VW owners manual specifications page. Look for the rpm for max torque. (1,750 to 2,500 rpm) This happens to "coincidently" coincide with the max efficiency. So if you have a DSG you want to firmly get to your cruising speed. If you want the best mpg run your rpm closer to 1,750. It will give you max torque and be at the lower end of the max efficiency range. (higher end mpg)

 

[Plus 3 Golfer]

Hello:
can you recommend a good highway cruising speed for best fuel economy with the Sportwagen TDI? 62 has been a sweet spot with my gas car, where its plenty fast, doesn't attract cops, and yields good mileage. I got better mileage at 62 than at 55.

Now I need to find the same sweet spot for the VW.

Rudy, read this thread. A slower speed in 6th gear will yield higher mpg as long as the engine is not lugging (say above 1300 rpm) but you will not be on the sweet spot of the torque curve (starts at about 1750 or so rpm) and hence acceleration will be slower at lower rpm.

If you want to find a balance between mpg and ability to accelerate without a downshift, I find that there's plenty of torque at 1800+ rpm in 6th gear. So, 1800 rpm or so equates to about 55/56 mph and 56 or so mpg but you will get better mpg driving slower.

 

[Derrel H Green]

Some Thoughts

Hello:
Can you recommend a good highway cruising speed for best fuel economy with the Sportwagen TDI? 62 has been a sweet spot with my gas car, where its plenty fast, doesn't attract cops,
and yields good mileage. I got better mileage at 62 than at 55.
Now I need to find the same sweet spot for the VW.

To quote from my friend in Arizona, "Rudy, read this thread.

By studying the handy dandy charts there, you will see what kind of
excellent Fuel Economy can be achieved by driving rather slowly.
In fact, almost too slowly for your safety when out on the interstates today.
Although I have done it, I seemed to be sending more time watching
for speeders in the rear-view mirrors that I did looking forward!

After you get your new JSW, and are familiar with everything, which will indeed take you
some time (!), find a level highway with as little traffic as possible, get up to say
50 MPH and set your Cruise control. Maybe you should wait until you have
accumulated some break-in mileage, because using the CC is not
recommended, at least right away in the beginning!

Anyhow, when you have your steady speed set, reset you MFD 1 and watch how
high the average MPG becomes. Of course, the slower you go up to a
point will determine how high that figure becomes!
But of course, driving on today's interstates at such low speeds is probably not safe
when everyone seems to be speeding at or even higher than the speed limits posted.

One thing you should do immediately if not sooner is to begin right away with a good additive.
Just as soon as you get your vehicle, go to a good station and add your additive and then fill
it up to the brim. It probably won't take much, but by adding more D2, you will mix the
additive with what is in the tank already. Usually the lot person does not always fill
the tank clear up to the brim because it is not their own car, don't you know?

The importance of adding a good additive cannot be minimized.
So do it right away from the beginning ASAP. I'm sure by now you have read why this is so important!

Good luck.



D

 

[PaulGiz]

I thought the point of these cars was that despite being comfortable and relatively roomy, you could drive normally, safely and pleasurably and still get very, very good mileage.

I don't have the patience to hypermile. I drive normally (occasionally briskly) and still get 38+mpg in winter and an easy 42 the rest of the year.

P.

 

[PlaneJob]

I thought the point of these cars was that despite being comfortable and relatively roomy, you could drive normally, safely and pleasurably and still get very, very good mileage.

It is. I drive mine on the aggressive side of normal... still getting better than 41 mpg.

I don't have the patience to hypermile.
P.

Apparently the OP does have the time/patience and wants to give it a try, eh?

 

[oilhammer]

I drive as fast as the boneheads I have to share the highway with will let me. The difference in fuel economy between driving 60 and driving 80 is a far smaller cost to me than spending less time on the road and more time working (earning money) and with my family.

That is why I like these cars so much, you can be a total lead foot and still be frugal.

 

[Ski in NC]

On my 2001 (admittedly a different beast) I have purposely tried different driving techniques on complete tanks. One tank, drive hard. Another tank drive like a pansy. I could hardly tell the difference in the per-tank calculated mpg.

Granted this was local/rural travel where peak cruising speed was not much different between tanks. On two-lanes, you go only as fast as the car ahead and passing opportunities are limited.

On interstate travel, 65 did get a few better than 75. Below 65 it is simply not safe as the cars behind you often are not paying attention.

 

[3rs]

Mileage

I am experiencing a level of frustration in finding a sweet spot with my JSW. Looks like 35 - 37 mpg is it. I now have 2300 miles. My old 2004 Jetta was 45 - 46 in town and 49-51 on road and it was an automatic.

 

[PaulGiz]

I am experiencing a level of frustration in finding a sweet spot with my JSW. Looks like 35 - 37 mpg is it. I now have 2300 miles. My old 2004 Jetta was 45 - 46 in town and 49-51 on road and it was an automatic.

Patience, grasshopper.

2300 miles isn't nearly broken in. Things will gradually improve as parts bed in and compression increases. Let us know how you're doing at 50K or so.

You won't match your '04 with a heavier, more restricted car, but you'll get better over time.

P.

 

[dpg]

I am experiencing a level of frustration in finding a sweet spot with my JSW. Looks like 35 - 37 mpg is it. I now have 2300 miles. My old 2004 Jetta was 45 - 46 in town and 49-51 on road and it was an automatic.

yea seriously patience!!! you're not even past the initial 5k break in point. just worry about breaking it in and after that initial 5k break in you can start to find that sweet spot. also, you're not going to get as good of mileage as you did with your '04. these cars have more emissions pieces that bring our mpg down slightly.

 

[jbright]

these cars have more emissions pieces that bring our mpg down slightly.

Not to mention a much more powerful engine.

 

[dpg]

Not to mention a much more powerful engine.

ahhh yes, and a bump up from 1.9L to 2.0L as well. its easy to see the difference when you compare the gal per hr between the 2 motors at idle

 

[Derrel H Green]

Your Sweet Spot . .

I am experiencing a level of frustration in finding a sweet spot with my JSW.
Looks like 35 - 37 mpg is it. [NO! That is too slow.] I now have 2300 miles.
My old 2004 Jetta was 45 - 46 in town and 49-51 on road and it was an automatic.

NO NO NO!

You are talking only 1128 to 1193 RPM if you are in sixth (top) gear,
and that is nowheres near your sweet spot! That's far to low RPMs.
Many here will tell you that you are lugging your motor, and that's not good.

Besides, where can you drive at that ridiculous low speed and not get run
over or cited for obstructing the flow of traffic?

If you want to know at what speed(s) your DSG equipped TDI will get the best F E (within reason!),
find a good level highway with little or no traffic (where is this possible?) and no wind.
Get up to whatever speed you wish to check it and then set your cruise control.
Now, reset your MFD 1, and drive for approximately five (5) miles in both directions and record
your MPGs. By repeating this procedure, you will be able to determine at what speeds it
will achieve the best Fuel Economy. Then and only then, based on that information,
will you be able to decide at what speeds you wish to travel and still be safe.

Very simple, but time (and fuel) consuming, but then you will know.
I think that you (and possibly others) may/will be surprised. I know I sure was!

In your case, because yours is so new, and not broken in yet,
many think it is best not to use the CC.
So perhaps you might consider waiting until you have more mileage on your odometer?

Enjoy your new car. I'm sure you must be doing so, or you would not be here.



D

 

[CDG]

50 mpg @ 60 mph
45 mpg at 65 mph
42-43 mpg at 70 mph

These are all estimates from the MFD, YMMV.

Winds can vary that number by +/- 10%.

And I have yet to find a gear where I get better MPG at 1750 rpm than I would at 1400. ESPECIALLY 6th gear. It is all about throttle position. Use your real-time MFD to see how that changes with your pedal-foot tendencies.

 

[Derrel H Green]

Your JSW has a DSG.



D

 

[oilhammer]

If I were stuck at a speed that placed the engine below 1900 RPMs in top gear, I would downshift into the next lower gear and drive like that. Lugging these engines is NOT good. You may think you are getting better fuel economy, but it won't ever net you as much as the turbo/intake/EGR/DPF repairs will cost you down the road.

As a very general rule, most engines perform the best bang for the buck where the torque peak and horsepower peaks are closest. On most TDIs, this is in the 2500 to 3000 RPM range, with the newer CR engines actually being on the higher end than the older type.

 

[Lightflyer1]

"Light foot"

Get to the speed you want, have a REALLY NIGHT FOOT, and you will get 50MPG. I did this at 80MPH on my Jetta tDI.

No one gets 50 mpg at 80 mph in these cars. The wind resistance alone will see to that. Maybe instantaneous when you let off the pedal. An instantaneous reading means nothing. If you can't do it for a full tank average, it is meaningless. You don't even have 5k miles on the car yet according to your signature.

http://forums.tdiclub.com/showpost.php?p=1280632&postcount=16

I know things are bigger in Texas, but that is a whopper!

 

[artemm]

I drive as fast as the boneheads I have to share the highway with will let me. The difference in fuel economy between driving 60 and driving 80 is a far smaller cost to me than spending less time on the road and more time working (earning money) and with my family.

That is why I like these cars so much, you can be a total lead foot and still be frugal.

This.

I let 'er rip and still get a pleasant surprise when it's time to fill up.

 

[phillypino215]

i just have fun when i drive then still have a smile on my face when i fill up.

 

[Lightflyer1]

When I did that trip the 2006's were new and no one really knew what they could do. That was only a test to see if it could get over 50 mpg and 800 miles to a tank. No one in their right mind would drive like that in real life. The speed limit in West Texas is 80 mph out there, and you know how fast people were driving. Some up to 100 mph. I had to be real careful and took the shoulder many times to let others pass. Keeping a careful eye behind and in front was essential. In real life I go with the traffic flow and try to enjoy the ride. My commute right now is 6 miles one way, so a tank lasts me a month or more. That is what I enjoy, filling once a month. Soon though it will be 70 miles round trip.

 

[ihatespeed]

Today I drove from portsmouth Virginia to boston, I saw 48 mpg, there was about an hour of stop and go in ny / ct and the overall average speed was about 52 I generally was cruising between 60 and 75.. I like to keep it in the 1800 rpm range, and just sorta take it easy. Unless you are in a no load situation, very little efficiency is lost by accelerating briskly in the power band. I generally shift just past 3000rpm, this lands the next gear right at 1900rpms. This is pretty much what I have been getting with a fully warmed up car, If I start making short trips I get more like 42mpgs.

 

[amycyclenut]

I took a road trip from Colorado to Oklahoma. 90% highway cruising speeds. Setting the cruise control to around 5mph higher than speed limits. So, in general I was running between 70-80 mph 90% of the way. At the time of starting out I had around 5K miles on the car. When I pulled into my dad's drive way it had taken me about 10 hours and my average mpg was 37.5. I can't lie and say I was a little disappointed. I mean, that's great mpg, but my car is a super car so I was hoping for 40's+ (and perhaps this lower mpg could be a result of the still low mileage?). Another thing I noticed, is about Kansas, my mpg start dropping considerably. Same driving speeds and habits on the hw, but the average number kept dropping. I think it got to around 35 or so and then about the time I was out of Kansas, it started going back up.

It is safe to assume this occurred because the car hadn't adjusted for altitude (i.e. diesel/air mixture)? I would think this kind of thing would be instant, afterall, it's all computer controlled.

Either way, my average was 37.5 for a 700+ mile trip.

One other thing, I hear ppl say all the time they drive their diesels hard and still get rock star mpg, but I drive my car like it's a ferrari around town and I still can't get out of the mid-30's.

 

[Derrel H Green]

Several Points

I took a road trip from Colorado to Oklahoma. 90% highway cruising speeds.
Setting the cruise control to around 5mph higher than speed limits. So, in general I was
running between 70-80 mph 90% of the way. At the time of starting out I had around
5K miles on the car. When I pulled into my dad's drive way it had taken me
about 10 hours and my average mpg was 37.5.
I can't lie and say I was a little disappointed. I mean, that's great mpg, but my
car is a super car so I was hoping for 40's+ (and perhaps this lower mpg
could be a result of the still low mileage?).
Another thing I noticed, is about Kansas, my mpg start dropping considerably. Same driving speeds and habits on the hw, but the average number kept dropping. I think it got to
around 35 or so and then about the time I was out of Kansas, it started going back up.

It is safe to assume this occurred because the car hadn't adjusted for altitude
(i.e. diesel/air mixture)?
I would think this kind of thing would be instant, afterall, it's all computer controlled.
Either way, my average was 37.5 for a 700+ mile trip.
One other thing, I hear ppl say all the time they drive their diesels hard and still get rock star
mpg, but I drive my car like it's a Ferrari around town and I still can't get out of the mid-30's.

Being as you have a DSG, your rpms will be higher at any given speed than with a 6 MT.
Hence, your F E will not be a high when out on the highway when going as fast as you were.

Your Golf is nowheres nearly broken in yet. Your F E will continue to improve with
more mileage on your odometer. Mine had almost 24K and is continuing to improve!

You did not say in which direction you were travelingf when your F E was 35 mpg.
Remembering when I was last in that area many years ago, isn't it a climb from
Kansas going towards Colorado? Since that is the case, of course
F E will not be as good as it was going the other way, will it?

Our CR TDIs will not ever get as good F E as the older VW diesels! This is common
knowledge and understood by all of us. It is not going to happen.

Another thing to consider: We are all suffering from having to use Winterized Fuel!
Make the same trip later when winterized fuel is not being used, and you'd see F E improvement.

Cut your speeds to no more than 70 mph for that same trip later
and watch your F E w/o winterized fuel get up to the mid 40s.

At 70 Mph, your rpms are 2256, which is past your point of obtaining good F E.

See: http://forums.tdiclub.com/showthread.php?p=3277168#post3277168
Notice what higher speeds do to F E. Observe the differences between 70 and 80 mph.



D

 

[amycyclenut]

Thanks Derrel, the direction of travel when I noticed the FE decline in Kansas was in route to Oklahoma, so elevation decline which at that point, I was likely not declining much at that point. On the way home, from OK to Colorado, the FE was actually pretty consistent through the entire trip (and that IS increasing elevation and also included a Thule rack system - where I actually expected to see a little less efficiency).

I also didin't consider the winterized fuel, which makes perfect sense and have wondered if it had an affect on FE, as I couldn't imagine otherwise.

Thanks for that chart, very cool to see. I need to take more long distance trips, I need more MILES!!!! Boy, do I f'ing love this car. And for the record, I don't worry much with mpg, just notice it and maintain a curiosity. And seeing how this was my first LD trip, I was really watching it. As a general rule I drive in "S" mode and not granny mode, drive it like a ferrari until some slow arse driver slows me down, and still get over 500 miles a tank. Which is better than any traditional gasser out there! So I'm happy.

 

[fs2k2k]

Forget the speed, look at the engine RPM, I keep mine under 2000 rpm at all times, even in the lower gears, (manual shift), at 2000 rpm in top gear, you will be doing 80 MPH, or 130 KPH, I still got great milage in the summer