[craig66]

I was wondering about fuel consumption and see reports of people getting 25, 30, 35 MPG.

I drive in a spirited fashion in sport only.
Very few highways
I have a new 4 month old 4K miles (broken in proper) PDK Base which I almost exclusively drive in manual mode

from a RPM POV I am:
6K a couple of times per drive
5K-6K 15% of the time
4K - 5K RPM 20% of the time
3K - 4K 30 % of the time
2.5K - 3K 35% of the time
2K - 2.5K 15% of the time
<2K ummm never

I am rarely in 7th gear

My average full consumption is around 18.5 MPG.
Is it really possible to get 30+ MPG aside from driving on a long highway in regular mode and in 7th gear at 60MPH on a windless day
Even when I am a "good boy" on a couple of my rides I cant seem to break 20 MPG

This is based on actual mileage with actual gallons pumped.

If this is to be expected I am fine with it - the extra gas per year is a minor part of the Porsche tax but just wondering if there is an issue with the car. Drives like magic and at 4K miles I would have expected the gas consumption to have evened out and even though I respected break in my consumption was not that different during breakin although I did not break 4.5K RPM's I still did spend most of the drives in the 2.5K-4K range

Thanks

 

[DPC]

I was wondering about fuel consumption and see reports of people getting 25, 30, 35 MPG.

I drive in a spirited fashion in sport only.
Very few highways
I have a new 4 month old 4K miles (broken in proper) PDK Base which I almost exclusively drive in manual mode

from a RPM POV I am:
6K a couple of times per drive
5K-6K 15% of the time
4K - 5K RPM 20% of the time
3K - 4K 30 % of the time
2.5K - 3K 35% of the time
2K - 2.5K 15% of the time
<2K ummm never

I am rarely in 7th gear

My average full consumption is around 18.5 MPG.
Is it really possible to get 30+ MPG aside from driving on a long highway in regular mode and in 7th gear at 60MPH on a windless day
Even when I am a "good boy" on a couple of my rides I cant seem to break 20 MPG

This is based on actual mileage with actual gallons pumped.

If this is to be expected I am fine with it - the extra gas per year is a minor part of the Porsche tax but just wondering if there is an issue with the car. Drives like magic and at 4K miles I would have expected the gas consumption to have evened out and even though I respected break in my consumption was not that different during breakin although I did not break 4.5K RPM's I still did spend most of the drives in the 2.5K-4K range

Thanks

I have a Base PDK and my gas mileage is very dependent on how I drive. On Saturdays I drive to a Cars and Coffee meetup and the trip is 50 miles by freeway. Cruising at 75-80 mph on 95% freeway, my car is getting 31-32 mpg. On the way home I hit some foothills with great 3rd and 4th gear curves, lots of braking and accelerating and my gas mileage drops like a rock. When I get out of the hills, my mileage improves and I usually end up at around 30mpg for the trip ( about 120 miles). I have about 8500 miles on the odo and 20" wheels. Considering the car's level of performance, I am very happy with the fuel consumption.

 

[DriveInHouston]

Your problem is that you are driving the PDK on ‘manual’. Driving the PDK on auto downshifting manually with the paddles and letting the car do the upshifting, will net you better mileage and more efficient driving. In the upshifts, the PDK will shift at a specific point depending on the position of the throttle and your tempo of driving, say x rpm. If you upshift early, you land on low(er) rpm than optimum. If you don’t, the PDK will upshift at the proper time, there is no way to ‘wait’.

On downshift however, the PDK doesn’t see the road ahead, a turn coming etc, so you can downshift ahead of the program when there is need.You can let PDK downshift and it will, depending how hard you are braking. Driving at the edge it may be a wash whether you do it or PDK.

 

[BillyX]

My average full consumption is around 18.5 MPG.
Is it really possible to get 30+ MPG aside from driving on a long highway in regular mode and in 7th gear at 60MPH on a windless day

I'd say yes. But like everything in life, it depends.

My DD is a 2019 Cayman base manual and in the summer I can get 32 mpg with 93 octane ethanol/premium gas at 70 mph with cruise control and a fairly flat highway with no interruptions or traffic.

Each leg of the daily commute includes about 45 minutes of rural, freeway and some hateful city driving. Average consumption with Sport Mode at 8,000 miles so far is 25.6 mpg over about the past 8 months. That consumption total also includes one DE day at Road America, at which time the mileage total decreased dramatically.

It all depends on your right foot. So, YMMV.

 

[craig66]

Your problem is that you are driving the PDK on ‘manual’. Driving the PDK on auto downshifting manually with the paddles and letting the car do the upshifting, will net you better mileage and more efficient driving. In the upshifts, the PDK will shift at a specific point depending on the position of the throttle and your tempo of driving, say x rpm. If you upshift early, you land on low(er) rpm than optimum. If you don’t, the PDK will upshift at the proper time, there is no way to ‘wait’.

On downshift however, the PDK doesn’t see the road ahead, a turn coming etc, so you can downshift ahead of the program when there is need.You can let PDK downshift and it will, depending how hard you are braking. Driving at the edge it may be a wash whether you do it or PDK.

That definitely makes sense. it was a hard switch from a MT to PDK and wanted to keep as much control as possible. I love the PDK and have no regrets but I agree maybe I need to let it do more of what it is designed to do and see what that does for my driving as well as my fuel consumption.

 

[jimmuller]

I didn't see where you used the term petrol or gasoline or simply gas. So I'm left to wonder if you mean those big British gallons instead of our smaller ones on this side of the pond. (Or did I get it backwards?) If you mean the smaller variety, well, I've gotten 35+mpg in my base Cayman by running legal speeds in 7th gear, non-sport mode. Even running in sport mode and sometimes 80mph to keep up with traffic I can get ~24mpg on my commute. So, no, the >20 figures are not mythical. Running 7th gear for long distances on the highway gives me over 32mpg.

 

[craig66]

I didn't see where you used the term petrol or gasoline or simply gas. So I'm left to wonder if you mean those big British gallons instead of our smaller ones on this side of the pond. (Or did I get it backwards?) If you mean the smaller variety, well, I've gotten 35+mpg in my base Cayman by running legal speeds in 7th gear, non-sport mode. Even running in sport mode and sometimes 80mph to keep up with traffic I can get ~24mpg on my commute. So, no, the >20 figures are not mythical. Running 7th gear for long distances on the highway gives me over 32mpg.

I am very much US based. If it was the British gallon my consumption would be even worse. We are definitely talking the smaller US gallons

 

[DriveInHouston]

I am very much US based. If it was the British gallon my consumption would be even worse. We are definitely talking the smaller US gallons

Nope, it takes fewer of the bigger gallons for a given distance, ergo, better mileage!

It also takes a gentle touch, even in Sport mode...

 

[craig66]

Nope, it takes fewer of the bigger gallons for a given distance, ergo, better mileage! View attachment 24721

It also takes a gentle touch, even in Sport mode...

I know I might be in a post turkey malaise but I am not sure I agree. If I was getting say 19 MPG of a British gallon which is 1.2 US gallons and so that 19 miles would translate to 15.8 MPG in the US making it worse fuel consumption. As I said I could be in a tryptophan haze. I guess it is also a little more complicated by the fact that in many countries gas is dispensed and priced in liters and distances is measured in kilometers and so a typical consumption might be listed as kilometers/liter.

Also I might have misnamed my Thread> I do believe it is entirely possible to get MPG in that range. What I really meant to was that for my type driving which is clearly very spirited without long high way spurts, is it possible to get better fuel consumption. Not into the 30 range but at least consistently above 21. I do like your idea of letting the PDK take a little more charge.

I did actually do a search (which is probably what I should have started off doing) and saw many numbers in the high and mid teens for people doing spirited driving that was mostly stop and start driving.

 

[dreamer]

I just went out and checked and I’m getting 21.7 for the first 1300 miles. Obviously, I’m still in run in phase but I’m not babying the CS (6MT). I see the 2000 mile redline (4000 rpm) occasionally. But I’m not really concerned about mpg so I don’t think that number is too bad.

 

[johan]

To get 25 Us mpg or above aint that hard to do even at highway speeds.
But it aint very fun

My normal drive to work on roads at 43 - 68 mph and me doing at least 10 mph over the limit ends up with 23 mpg.
If i am in a hurry i get 18mpg and my record is 32 mpg
My average for driving ( daily) according to the pcm is at 28 mpg now when it is winter, in the summer i am at 22 mpg

 

[718Niko]

O my ~19miles comute, which is a mix of country side roads, highway and city driving, Im usually averaging 31-32mpg, sometimes going up to 33~.
In winter it does drop a bit sometines the ac + heated seats + heated wheel i guess?), arround the 28-29 mpg.

Even if I put her on sport mode and drive harder im usually arround 24-25.

 

[jimmuller]

I know I might be in a post turkey malaise...

He! Good point. It all points to one's perspective, doesn't it?

In fact, gas mileage, i.e. distance traveled per unit volume of gas/petrol/gasoline/whatever under any given driving conditions, is the same regardless of the units one uses to measure it. If you use big British gallons you get a bigger number miles per gallon. If you got the same number for those big gallons then your actual mpg is less, implying that you drive, um, spiritedly.

I like to use miles per tankful. (This being the Tanksgiving weekend, I'm tankful for being fortunate enough to have a car like the C. But that's another story.) Some of us have different size tanks so even if we drive the same we wouldn't all run out of gas at the same distance from home.

You could add mileage figures from n cars and divide by n. That would the arithmetic mean.
You could multiply mileage figures from n cars and take the nth root. That would the geometric mean.
You could ask n people for their mileage to get an overall sense. That would be the yanowada mean.

Ya' know what I mean?

 

[718Niko]

Allways thought Liters per 100km was a much better way to get an idea of how much a car drinks.


And not only because the metric system is better.

 

[EuroKip]

Like most, I get 32 on highway. 9mpg on the track
It was fun to see the low fuel light come on showing 1/3 of a tank remaining with 50 miles to empty. When filling up from that point, it it showed 150 distance till empty. After a days drive on highway the computer finally recalibrated back to my normal. What happens if our cars go to electric in a couple of years ? Will we need a trailer to get the car home for a recharge after a couple of sessions with the go pedal ?

 

[DriveInHouston]

It does get complicated, doesn't it?

If you use the bigger, more aristocratic Imperial Gallons, 10 gallons will get you further than 10 plebeian, puny US gallons, implying that you get worse mileage with US Gallons!...

I have to admit that I freaked out, when I heard the cousins over the pond getting 37-38 mpG, when the best I could do was 33 mpg... And this driving on the freeway, in Normal (aww the shame) with Cruise Control. Once I got satisfied that I can get 33 mpg, I switched back to Sport and never looked back. I do use CC on the freeways, because I can get ...distracted... and glimpse 85 on the display...

 

[alf_17]

It has been a while now since I have driven my Base 718 Boxster with PDK, but I seem to recall that when not hammering it I get around 10 km/l average which is around 25mpg (US).

 

[highwire_ca]

It has been a while now since I have driven my Base 718 Boxster with PDK, but I seem to recall that when not hammering it I get around 10 km/l average which is around 25mpg (US).

In mixed city and highway driving, I average about 10litres per 100km (23.5m/USg). Highway driving (130km/h) I average about 7litres per 100km (33.6m/USg). That's with a 2017 Cayman S with PDK in sport mode.

 

[DriveInHouston]

For convenience, x lt/100 km = (220/x) mpg , y mpg = (220/y) lt/100 km

Approximately...

 

[CaymanMatt]

Our CGTS gets around 21-22 mpg when driven reasonably aggressively on the roads here in VT/NH. I get around 25-27 mpg when on the highway in cruise control mode. I'm sure it will plummet when driven on the track.
YMMV