brodiakbear
Member
So I am a first time ever tdi owner! Just picked up a 2014 Jetta tdi 6 speed manual! I've had it for 2 days now and I'm absolutely in love lol. Like the title said, What's the best cruising speed I'm order to achieve high MPG.
Best speed for MPG?
- Thread starter brodiakbear
- Start date
DieselRacer
banned
55mph would yield the best mpg and not get you run over on the highway, try not to brake a lot, and accelerate by shifting at about 2500rpm to 3g, you should get in the high 40's doing this, if not more...
Fav40
Veteran Member
- Joined
- Nov 3, 2013
- Location
- Orange County NY
- TDI
- 2014 Passat TDI SEL (BB 2/17/17) 2017 Passat V6 SEL Premium
The manual cruise rpm at a given speed should be lower than the same speed with DSG.
With that said, I have found 70mph or lower yields good mpg's with my DSG Passat.
With that said, I have found 70mph or lower yields good mpg's with my DSG Passat.
gulfcoastguy
Veteran Member
Are we talking about level highway speed? I can tell you that a little slower is better but some boy racers are going to tell that it doesn't matter and to stay out of the left lane. That said on a long, flat level drive at 65 mph I'll eventually hit 50 mpg but off course the tank average is a bit less. At 70 mph it is probably about 3 mpg lower. I don't go any slower than that on the interstate, in fact the 65 mpg is pretty much limited to night time when the traffic count is lower. City driving is too variable to guess.
JohnWilder
Veteran Member
As slow as you can go in top gear.
Max Period
Veteran Member
Data from Motor Trend's Comparison: 40 MPG Compact Sedan, in nearly perfect conditions, with the 10% energy content adjustment removed:
Metric unit graphs:
US customary units graphs:
Metric unit graphs:
US customary units graphs:
hybridkiller
Veteran Member
Bear in mind that your mpg numbers will steadily improve (slightly anyway) as the engine breaks in, and diesels take tens of thousands of miles to fully break in.
At ~38K miles, if I keep it below 65mph I can break 50 mpg avg hwy under ideal conditions (warm ambient temps, no headwind, AC off)
The great thing about TDIs is that "absolutely in love" feeling never wears off.
Last edited:
DieselRacer
banned
Awesome charts, next time make them a pie chart, I'm hungry...
StevieDTDI
Member
In cruse control the DSG will shift from six to five on long down hill to maintain set speed. Try to slightly increase speed on down hill or take cruse control off.
hybridkiller
Veteran Member
You meant uphill, right?
Last edited:
hybridkiller
Veteran Member
I agree. And for those who are really gaming the mpg thing, constant throttle (or fuel delivery, I guess technically diesels have no throttle) - letting your speed drop - is generally the cheapest way to climb that hill (assuming you hit it with enough speed to avoid downshifting - which is what I think you were saying).
Last edited:
TJGarvin
Veteran Member
The DSG will downshift to maintain the set speed going uphill or downhill. It will also get VERY aggressive on the downshift when you combine downhill and braking for the light at the bottom.
hybridkiller
Veteran Member
If your DSG is downshifting, going downhill, while maintaining steady speed, then there is something wrong with your tranny (which I doubt).The DSG will downshift to maintain the set speed going uphill or downhill. It will also get VERY aggressive on the downshift when you combine downhill and braking for the light at the bottom.
You may be feeling engine braking when coasting downhill and you are mistaking that for downshifting - if you're accustomed to slushbox ATs the DSG feels more like a MT in that regard. The DSG ALWAYS downshifts though every gear as you coast/brake to a stop - nothing to do with hills. I think we were mainly talking about steady-state hwy cruising.
You can always confirm by nudging your shift lever momentarily into tiptronic mode, and your MFD will display the current gear you're in (without causing a manual shift).
Last edited:
TJGarvin
Veteran Member
Been there, done that. Nudged into tiptronic to confirm and check. Speed limit at 80 kph (50 mph), cruise set to 90 kph (56 mph). It will downshift from 6 to 5, on it's own, on a steep(ish) hill, where normal engine braking does not hold the vehicle back and it accelerates beyond the set speed. As soon as you run out onto the flat, it then upshifts back to 6. I run that hill every day on my commute and it does the downshift at that point.
The behavior that I mentioned and called "aggressive" (for a slushbox that is
) it will do, when braking hard for a stop from 90 kph with the steep hill added into the mix (different hill and a different road). I've had the DSG row itself down through the gears from 6th through to 3rd while it kept the revs above 2500, all by itself. A very different behavior and RPM range from the normal downshift pattern when coasting down and the usual easy brake to a stop while on a flat. Very disconcerting when you're not expecting it. Which is why, for testing the behaviour, and training myself in what my Black Beauty will do, I deliberately put the car through those paces on that hill. I hate being surprised by any vehicle, any time, for any reason. I apologize to the OP for getting off topic here, but I think the DSG is the most advanced transmission I have every had the privilege of owning and operating. What I just described here is, to me, a feature, not an issue.
mohawk69
Veteran Member
Google "HYPERMILING" and start reading. Speed is only one factor and there are many things you can do to save fuel although most are unwilling to do most of them. For instance, it's hard enough to keep the car cool already with all the foam gone on the blend door. I'm certainly not going to turn the AC off even if it costs 30 mpg's to keep it going. And, if you're going to go slow to save fuel, do it in the RIGHT lane. This boy racer is getting militant.
hybridkiller
Veteran Member
Ok, now I understand what you are saying, but you are losing some of the payback you should be getting on the downhill side (we're still on-topic btw). I tend to toggle CC off when climbing steep hills, keep the go pedal steady and let it bleed off some speed, coast downhill (CC still OFF) and don't resume it till I approach the bottom of the hill.
If the downhill is steep enough to maintain speed or even gain a little I just let it go, if not I bump it into neutral if it's a long hill (again, this would be straight up hwy with no traffic lights). The only time I want a downshift to engine brake (not rolling to a stop) is in the mountains - that's when tiptronic comes in really handy (the Golf's flappy paddles are perfect for that).
If I had to guess, I'd say that most hypermilers are, by definition, very conscious of what they are doing - and probably want to stay out of your way. Most of the people I see holding up traffic in the left lane just seem oblivious in a general sort of way. I doubt there's any direct correlation between hypermiling, and lacking consideration for the people they share the road with.
Also, if you're hypermiling you HAVE to learn to coexist rather closely with big-rig drivers, and they take a VERY dim view of anyone who interferes with their momentum (and anyone who's ever driven a truck with a big payload understands why).
Last edited:
This.
I drive a big rig for a living, and I also "hypermile" slightly. Mostly I just drive slow in the left lane and coast in neutral and much as I possibly can. Typically Im not the one holding up traffic. I do as much as I can without pissing too many people off. I wish I could do 45 all the time, but I usually keep it 55 if someone is behind me (speed limit on my route is mostly 55 mph anyway) and 50 is its clear behind me. If going the speed limit is pissing people off tho, I usally say "eff em" and maintain 55.
mohawk69
Veteran Member
Did you mean to say you just drive slow in the LEFT lane? And, I'm guessing you're not being paid by the mile if you go only 50 when you can. Is that correct? Sure, getting great mpg's is good but there's always the value of time too.
Oh shoot, I mean I drive slow in the right lane in my VW going to and from work. I drive truck locally and am paid hourly, and I dont hypermile in my truck. Lmao.
Slurry Pumper
Veteran Member
The best MPG happens when you can find a truck to tailgate. Other than that, keep out of the left lane so I can pass. Does anyone's who is looking for the max mileage ever compute the TIME aspect. For instance, I drive for an hour at 75 MPH, and then take a 30 minute nap while waiting for someone to catch up who is driving at 50 MPH. Sure I got around 45 MPG and the other dude got 50MPG +, but what is the value of the time difference? At today's price of diesel around Philly, ($4.00), I used 1.67 gallons of fuel, while the other guy used 1.5 gallons. The .17 represents 68 cents. My half an hour rate for anything is slightly higher than .68 cents. None of these numbers are scientific, but just used as an example.
Zlartibartfast
Veteran Member
My TDI is a manual 6, almost an apples-to-oranges ocmparison, but I have learned two things:
1) below 1800 RPM I'm losing efficiency (the engine reaches max torque @ about 1800)
2) when I keep it in gear, and lift off the accelerator to coast downhill, the fuel stops flowing. This results in MPG's above 99 (off the scale of the computer).
I get best MPG @ 58 MPH - have twice recorded 52.
I took a 600 mile trip averaging 75MPH (80 MPH limit) and got 39, with the car fully loaded.
I also have a Jeep w/3L V6 CRD - it hits max torque @ 1650 RPM, and has a 5 spd automatic w/3:73 rear gear. It's most efficient speed is 50MPH, where it can get up to 30MPG. Driving 75MPH in that car yields 23 MPG.
Tire pressure, humidity, air temp, road surface, and a whole slew of other factors all play a role in your real world results.
1) below 1800 RPM I'm losing efficiency (the engine reaches max torque @ about 1800)
2) when I keep it in gear, and lift off the accelerator to coast downhill, the fuel stops flowing. This results in MPG's above 99 (off the scale of the computer).
I get best MPG @ 58 MPH - have twice recorded 52.
I took a 600 mile trip averaging 75MPH (80 MPH limit) and got 39, with the car fully loaded.
I also have a Jeep w/3L V6 CRD - it hits max torque @ 1650 RPM, and has a 5 spd automatic w/3:73 rear gear. It's most efficient speed is 50MPH, where it can get up to 30MPG. Driving 75MPH in that car yields 23 MPG.
Tire pressure, humidity, air temp, road surface, and a whole slew of other factors all play a role in your real world results.
Slurry Pumper
Veteran Member
Just to use Zlartibartfast's example:
At 75 MPH and 39 MPG over a 600 mile distance, he used 15.385 gallons of sweet diesel, and got the driving over with in 8 hours.
At 58 MPH and 52 MPG over a 600 mile distance, he would use 11.538 gallons of diesel, and get the driving over in 10 hours 20 minutes and around 41 seconds.
At $4.00 a gallon, he would have spent (3.847 gal * $4.00) = $15.39 more to get there 2 hours 20 minutes and 41 seconds earlier. The average price per hour would be around $6.56.
With tthis information, I would still take the 75 MPH scenario and consider it a better deal.
At 75 MPH and 39 MPG over a 600 mile distance, he used 15.385 gallons of sweet diesel, and got the driving over with in 8 hours.
At 58 MPH and 52 MPG over a 600 mile distance, he would use 11.538 gallons of diesel, and get the driving over in 10 hours 20 minutes and around 41 seconds.
At $4.00 a gallon, he would have spent (3.847 gal * $4.00) = $15.39 more to get there 2 hours 20 minutes and 41 seconds earlier. The average price per hour would be around $6.56.
With tthis information, I would still take the 75 MPH scenario and consider it a better deal.
gulfcoastguy
Veteran Member
The majority of people are going 100 miles per trip or less. we are talking just a few minutes difference in 70 mph or 65 mph on such a trip. Now highways that I drive on have speeds of less than sixty five except the beach highway, US 90, and it has traffic lights every half mile or less. The longest trip I've taken was 245 miles one way to see a dog breeder. the last 40 or 50 miles was twisting secondary county roads in Alabama.No way to do even 55 on most of that.
Max Period
Veteran Member
SUVs have higher fuel consumption penalty than cars for increased cruising speed, due to their larger frontal area and drag coefficient.
This holds true for the Touareg TDI too.
The Touareg Hybrid's fuel consumption rises exceptionally sharply for higher speeds, compared to any other car (including the Touareg V6 TDI)
This holds true for the Touareg TDI too.
The Touareg Hybrid's fuel consumption rises exceptionally sharply for higher speeds, compared to any other car (including the Touareg V6 TDI)
Last edited:
L w
How often do you take trips over 100 miles??? I dont take them very often. We are talking about commutes to work all week. My commute is 25 miles each way, all highway. When I go 50 it takes me 30 mins, and if I went 65 it would take me 23 mins. It is WELL WELL worth it to me to leave 5 mins earlier to get the extra fuel economy. So far Ive averaged a touch over 60 mpg since I bought my car a couple months ago, and Im on pace for over 65 mpg this current tank. For me, seeing those numbers is worth the extra few minutes.
I also have a Jeep GC CRD
How often do you take trips over 100 miles??? I dont take them very often. We are talking about commutes to work all week. My commute is 25 miles each way, all highway. When I go 50 it takes me 30 mins, and if I went 65 it would take me 23 mins. It is WELL WELL worth it to me to leave 5 mins earlier to get the extra fuel economy. So far Ive averaged a touch over 60 mpg since I bought my car a couple months ago, and Im on pace for over 65 mpg this current tank. For me, seeing those numbers is worth the extra few minutes.