Average MPG

[usman10316]

Just filled up my Boxster today, to my surprise, I seem to be getting quote good MPG figures on the 2.5. From half a tank, as soon as the light came on I filled the car up and put in 50 litres (from a 62 litre tank). So I assumed I used around 20 litres for 190 miles which equals out around 40-43 MPG.

Of course, this is just rough estimation, so if anything I would be getting around 39-43 MPG which isn't bad at all IMO. I was driving around 50mph though - so if I'm at 70, I guess around 30 MPG.

Also my working times have changed so I'm working a 4pm until 12am shift. That means that I usually drive when there is no traffic on the road, so it is more or less continuous driving all the way home. I do get stuck in a bit of traffic from the school runs, but nothing like rush hour traffic.

[Anker BS]

You are way, way, way off!

Do it properly: fill the tank completely, drive till it is close to empty, fill it up again, use the amount of fuel that it took and the mileage since the first fill. Then you are going to get somewhere between 25 and 30 mpg.

Needle position is notoriously inaccurate!

[usman10316]

9 minutes ago, Anker BS said:

You are way, way, way off!

Do it properly: fill the tank completely, drive till it is close to empty, fill it up again, use the amount of fuel that it took and the mileage since the first fill. Then you are going to get somewhere between 25 and 30 mpg.

Needle position is notoriously inaccurate!

See, I've filled the tank up and done this, I got 40 MPG - but was very careful when driving and conservative.

So its not impossible by any means - but, I will update what I get this time as well.

[K.I.T.T.]

As above - the needle moves down quicker at the top of the gauge due to the shape of the tank.

I've been averaging 26 MPG over 7.5k, predominantly motorway, miles. Calculated by brimming the tank and resetting the odometer.

[PaulQ]

I don't bother calculating mine anymore, but when I did the average was mid 20's

Have had low 30's a few times on long runs though.

[Boxob]

Max reading on OBC was 35mpg after careful motorway driving. Now sits on a steady 28.6 mpg with mixed driving. Pushed hard I'd expect 20-25mpg. 40-43mpg doesn't seem feasible unless I was being towed for part of the journey!

[usman10316]

Mmm - yeah, 40mph motorway driving when it's clear is ok. But I know it's not what the Porsche was made to do. 

 

I mi have my obc enabled just need to wire in the switches for it. I have however read on other forums of people also achieving 40 mpg. I know it's all route and driving variables but it is achievable if you have patience, which many won't. 

[usman10316]

The Cayman averages 30mpg at 70-80 on the motorway pretty easily. 

[Paul Fisher]

I can achieve 340 miles on a tank of fuel on my 64 mile daily commute which is a mixture of 65/70mph dual carriageway and stop start traffic. This equates to around 28 mpg which I think is pretty good. I think along journey at steady 70/80 mph then I guess 30+ mpg is achievable but I'm guessing around town the average plummets.

I'm happy with 28mpg, my diesel Audi only averaged 40mpg.

[Stuart21UK]

1 hour ago, Paul Fisher said:

I can achieve 340 miles on a tank of fuel on my 64 mile daily commute which is a mixture of 65/70mph dual carriageway and stop start traffic. This equates to around 28 mpg which I think is pretty good. I think along journey at steady 70/80 mph then I guess 30+ mpg is achievable but I'm guessing around town the average plummets.

I'm happy with 28mpg, my diesel Audi only averaged 40mpg.

if the tank is 64 litres (?) then that's 24.2 mpg isn't it?

62 litres would equate to 24.9 mpg....

.....either way your doing your brethren proud  

[Billzeebub]

My various 3.2 986s have generally  averaged around 34mpg on a motorway/a road trip, around 25mpg mixed driving 

[the baron]

I do a lot of miles and don't bother with this type of calculation anymore, but I have done it religiously in the past.

the only way to do it is to run the car down to fumes, fill it right up and take note of how much you have put in the tank, " fill, drive, repeat "

i get around 32-36mph on average, if I did a lot of spirited driving mid twenties maybe less.

[edc]

I don't measure my mpg round here but on Euro trips I average around 20mpg. 

[usman10316]

I know the needle can be a bit odd on these things. I have my OBC enabled just need to get the wiring done up sometime as I think the miles till fill up required would be cool to have and I usually go by that on cars with OBC. 

Just got back home from work. Terrible weather meant I was cruising around 40-45 on a quiet motorway. Added about 10 minutes to me getting home which isn't the end of the world. 

[MakeTeaNotWar]

11 hours ago, Billzeebub said:

My various 3.2 986s have generally  averaged around 34mpg on a motorway/a road trip, around 25mpg mixed driving 

That's what I've been getting, not bad for a 3.2 really, I've also found it much easier to achieve better MPG since having cruise control retro fitted, its probably paid for its self already.

[Billzeebub]

That's on my to do list for the next couple of months. Especially with the ridiculous amount of average speed camera stretches on UK roads now. 

[james_ly]

My commute's around half motorway, half town, so I get 25mpg which is ok. With no motorways I think it would definitely dip below 20, the noise is so much better on cam over 5k rpm

[usman10316]

Drove  the Cayman today, I got 28MPG - but realised I had the A/C on... so could have hit 30 maybe? Was a 17.5 mile there and 17.5 miles back. 

Wish I could get cruise control on mine, but I've been told its not possible, then again, I always like being involved with the driving as much as possible. 

[Gutley]

5 hours ago, usman10316 said:

Wish I could get cruise control on mine, but I've been told its not possible...

Told by whom? Not saying they are wrong as you don’t say what Cayman you have. 

[usman10316]

3 hours ago, Gutley said:

Told by whom? Not saying they are wrong as you don’t say what Cayman you have. 

Sorry. The Cayman has cruise the boxster doesn't. I should have been more specific! 

[Gutley]

Ok. I guess it doesn’t have the egas. If it does it should be retrofitable 

[T24RES]

Pre-egas is doable.

https://www.renntech.org/forums/topic/3532-adding-cruise-control-to-a-my98/

 

Bit of research and you'll find the parts required

[usman10316]

yesterday I finally got around to opening up the instrument cluster to wire up the buttons for my OBC. As I was there also fit in a mic, sadly it's not very good but I guess it will do the job. 

Took ok it for a spin yesterday through a nice local carriageway and saw 36mpg on it. As I got local I got 32. 

I guess if i I drive fully local this will drop to about 22-24 as my area is always up hills :/ 

looking forward to the work runs of course. May also try some hypermiling just to see what I can get. 

I know boxsters aren't really for MPG but it's nice to know a decent result is achievable driving sensibly. It also reminds me why I didn't get an S as the car is my daily I think fuel would become very costly. 

[usman10316]

On ‎07‎/‎10‎/‎2017 at 12:39 PM, T24RES said:

Pre-egas is doable.

https://www.renntech.org/forums/topic/3532-adding-cruise-control-to-a-my98/

 

Bit of research and you'll find the parts required

$250 Australian dollars doesn't sound too bad! I wonder how much Revolution would do this for. 

[Cocky]

I got 40mpg once being towed when my clutch had gone. 

What tyres do you have? I've noticed my mph rising with my sport contacts. Getting 25/26 on a Dales spring and roughly 27 the rest of the time but my cars a toy and I couldn't handle going 40 on a empty motorway.