Trip computer mpg accurate?

Silverzedtom · Post by **Silverzedtom** » Wed Feb 22, 2017 8:19 pm

As above I also reset the mpg and mph averages after a full tank.

I get about 25mpg when pottering around locally. I am in a long distance relationship so spend many hours on the motorway and consistently get 30-34 mpg, even with the odd right foot heavy moment. That's in a 2.5si, but from what I've read the consumption isn't worlds apart from the thirstier 3L.

I can't say as to how accurate the computer is as I've never been bothered to do the maths.

Whilst we are talking about the trip computer I always reset the miles traveled after washing her. Interesting to see how many miles it's been since the last. Sad I know...

mmm-five · Post by **mmm-five** » Wed Feb 22, 2017 8:36 pm

Marius wrote:That's probably takes 17min to do one lap, haha

10m01s was my fastest lap when I went out there last October - which is not bad for a 115bhp diesel

(was supposed to have been in the Z4MC, but there was a last minute hitch with the garage doing my diff, when the newly installed 4-post lift failed)

Fastest bits were the run to Schwedenkreuz and down into Fuchsröhre (both showing 120mph on the clock). Worst bit was the climb up Kesselchen to Steilstrecke where I couldn't put it into 5th and had to keep it screaming in 4th to get it to sit at 90mph.

It was so much fun that I had to buy more lap tickets, because everyone was asking for a passenger ride.

In the damp, greasy, murky conditions in the mornings it's relatively on the pace with anything else out there

It's off to Cadwell Park on Saturday too

buzyg · Post by **buzyg** » Wed Feb 22, 2017 11:54 pm

Smartbear wrote:
buzyg wrote:
mmm-five wrote: 14mpg actually, which really pisses off my e34 M5 friends, as they're getting sub-10mpg

I'm not chasing times anymore, so change up no later than 7000rpm, and I'm not particularly slower than I was before. Traffic affects consistency more than my acceleration, and I even do an 'economy' challenge where you still have to be under 10 minutes but can use whatever gears/revs you like. Best was 20mpg in mine (before I took the Alfa JTD of course - that's about 35mpg when wringing its neck).

I was sub 10 mpg in the Fiat around the ring. Only done Spa in the Zed and didn't work out mpg properly. I was using all 8k for the first few laps, up the main straight, chasing a 996 porker turbo. Then I took pity and started changing into 5th. Still couldn't keep up with my mates 2ltr ford duratec lump though.
What was it in, a caterham 7?
Rob

No it was in this.

https://www.youtube.com/watch?v=65hR2i8 ... z3hsQuAlAw

co-pey · Post by **co-pey** » Thu Feb 23, 2017 1:32 am

3.0si with no mods, and running a stock air filter. I get 30mpg on the interstates with the cruise control locked down at 80mph. 20-25 in the city. I've done the math enough to trust the computer mpg 100%! Most accurate trip computer I have ever had in a car.

Yorkie Z · Post by **Yorkie Z** » Thu Feb 23, 2017 7:59 am

Chris_D wrote:Fuel economy? You all fail!
I fail at taking photos however, so it all balances out really
image.jpeg

No you fail!!! You need to hand your car keys to a really petrol head. Clearly you're just an old granny

My old Z and a track day

Smartbear · Post by **Smartbear** » Thu Feb 23, 2017 9:48 am

buzyg wrote:
Smartbear wrote:
buzyg wrote:

I was sub 10 mpg in the Fiat around the ring. Only done Spa in the Zed and didn't work out mpg properly. I was using all 8k for the first few laps, up the main straight, chasing a 996 porker turbo. Then I took pity and started changing into 5th. Still couldn't keep up with my mates 2ltr ford duratec lump though.
What was it in, a caterham 7?
Rob
No it was in this.

https://www.youtube.com/watch?v=65hR2i8 ... z3hsQuAlAw

That sounded good, obviously forced induction Buzy-do you know how much power it produces?

Rob

Chris_D · Post by **Chris_D** » Thu Feb 23, 2017 11:20 am

Yorkie Z wrote:
Chris_D wrote:Fuel economy? You all fail!
I fail at taking photos however, so it all balances out really
image.jpeg
No you fail!!! You need to hand your car keys to a really petrol head. Clearly you're just an old granny

Not at all! There's a time and a place, so why hoon it on the motorway? It's pointless.
Perfectly happy to waft through a motorway journey, especially here in mainland Europe - set cruise to 65mph, Pink Floyd on the stereo, top down if it's sunny. Arrive at destination eminenty relaxed and maybe a bit more tanned!

Don't get me wrong - I've done my fair share of 'ring shennanigans and I still like to scrub a millimetre or two off the rears on the quiet backroads of Holland but if I'm on the snelweg, with other motorists around, and the Dutch seem to have a particularly aloof driving style I have to say, then why bother driving like a tw@t?

mmm-five · Post by **mmm-five** » Thu Feb 23, 2017 12:01 pm

Yorkie Z wrote:No you fail!!! You need to hand your car keys to a really petrol head. Clearly you're just an old granny

My old Z and a track day

Obviously using the wrong gears

If we're going into tyres and any old track, then the old Anglesey circuit at 0.9 miles and never out of 3rd would even let the M5 get 10mpg.

Elvington on the other hand was quite good on fuel, but the M5 ate rear tyres when you slide it around too much...

....sorry for the poor quality video, but this was from the days of VHS camcorders and was digitised some time later by Jimbocam on a Bookatrack trackday...

Yorkie Z · Post by **Yorkie Z** » Thu Feb 23, 2017 12:02 pm

Chris_D wrote:
Yorkie Z wrote:
Chris_D wrote:Fuel economy? You all fail!
I fail at taking photos however, so it all balances out really
image.jpeg
No you fail!!! You need to hand your car keys to a really petrol head. Clearly you're just an old granny
Not at all! There's a time and a place, so why hoon it on the motorway? It's pointless.
Perfectly happy to waft through a motorway journey, especially here in mainland Europe - set cruise to 65mph, Pink Floyd on the stereo, top down if it's sunny. Arrive at destination eminenty relaxed and maybe a bit more tanned!

Don't get me wrong - I've done my fair share of 'ring shennanigans and I still like to scrub a millimetre or two off the rears on the quiet backroads of Holland but if I'm on the snelweg, with other motorists around, and the Dutch seem to have a particularly aloof driving style I have to say, then why bother driving like a tw@t?

Pink what?

Yorkie Z · Post by **Yorkie Z** » Thu Feb 23, 2017 12:04 pm

mmm-five wrote:
Yorkie Z wrote:No you fail!!! You need to hand your car keys to a really petrol head. Clearly you're just an old granny

My old Z and a track day
Obviously using the wrong gears

If we're going into tyres and any old track, then the old Anglesey circuit at 0.9 miles and never out of 3rd would even let the M5 get 10mpg.

Elvington on the other hand was quite good on fuel, but the M5 ate rear tyres when you slide it around too much...

....sorry for the poor quality video, but this was from the days of VHS camcorders and was digitised some time later by Jimbocam on a Bookatrack trackday...

Nice

That looks a whole lot of fun. That's the problem with living in Devon, all the good tracks are miles away.

buzyg · Post by **buzyg** » Thu Feb 23, 2017 4:45 pm

Smartbear wrote:
buzyg wrote:
Smartbear wrote:
What was it in, a caterham 7?
Rob
No it was in this.

https://www.youtube.com/watch?v=65hR2i8 ... z3hsQuAlAw
That sounded good, obviously forced induction Buzy-do you know how much power it produces?
Rob

It was around 400 bhp. But he keeps fettling it. Has a sequential box now too. So faster than it was there.

ben g · Post by **ben g** » Thu Feb 23, 2017 10:49 pm

BradleyB wrote:Yeah reset it! I reset the mpg every time I fill up and put the mileage, fuel price and litres into an app on my iPhone. I then compare the figures and the car always seems to calculate a bit higher than what I'm actually getting!

Buy a Prius.

buzyg · Post by **buzyg** » Fri Feb 24, 2017 12:12 am

ben g wrote:
BradleyB wrote:Yeah reset it! I reset the mpg every time I fill up and put the mileage, fuel price and litres into an app on my iPhone. I then compare the figures and the car always seems to calculate a bit higher than what I'm actually getting!
Buy a Prius.

NNNNNNooooooooooooooooooooooooooooooooo!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Mr Tidy · Post by **Mr Tidy** » Fri Feb 24, 2017 12:45 am

Had a new battery in my E86 on 29 December 2016, so all averages were reset then.

I don't use it to commute or in rush hours - also don't use it for short local trips (to avoid parking damage)!

Typical trip is 30+ miles each way using the M3 (50 mph average), M25 (with cameras) then A3 (no cameras, just look out for the vans)!

300 or so miles later my average speed is 37.8 mph and mpg is 31.7 - happy with that!

What I don't know is how accurate the mileage recording is though!

FWIW my 325ti daily (same engine as a pre-facelift 2.5) is showing averages of 31.8 mph and 34.7 mpg after 2 years and 16K miles, and that does do the shopping runs (to save the Z4C)!

Obviously need to try harder.

BradleyB · Post by **BradleyB** » Fri Feb 24, 2017 9:02 am

ben g wrote:
BradleyB wrote:Yeah reset it! I reset the mpg every time I fill up and put the mileage, fuel price and litres into an app on my iPhone. I then compare the figures and the car always seems to calculate a bit higher than what I'm actually getting!
Buy a Prius.

It's more to track the miles I do each year but thanks for the advice..

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