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On 6/12/2019 at 10:16 AM, Pinewood said:

I'm getting 30mpg from 3.4 gen2  PDK - think i need to drive it harder 

No, they're the most frugal of the bunch.  If I'm not in a hurry and flick the cruise on at 65mph, I'll get 40mpg from mine as long as it's a long enough distance.  It takes ages to warm up the engines properly and the 10 mile each way commute will only yield mid 20s.

Seeing Pothole's figures makes me realise why he was accused of ragging a sellers car.

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37 minutes ago, Araf said:

No, they're the most frugal of the bunch.  If I'm not in a hurry and flick the cruise on at 65mph, I'll get 40mpg from mine as long as it's a long enough distance.  It takes ages to warm up the engines properly and the 10 mile each way commute will only yield mid 20s.

Seeing Pothole's figures makes me realise why he was accused of ragging a sellers car.

They would be a banning offence in my 🌎 that’s what family cars are for. 😊 per gallon is the only way to drive your 📦A. 

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Whenever I change cars (from the M4nster to the hybrid RAV4) I feel the wallet is taking a long sigh of relief :laugh:

xa-rf2XMBM08GKKm0icVV6meiTVb5tgTZmXzLVDw

vs

juu-2g5buSL_IL2mLoyroTpwzCrbC0twHTCfJ_hB

 

First was after a "hard" day in the Pyrenees, the second just a leisurely city night drive.

Edited by j0hn

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On 6/13/2019 at 9:45 PM, Araf said:

 

Seeing Pothole's figures makes me realise why he was accused of ragging a sellers car.

Why is that, then? Very cheap shot, but not a huge surprise coming from you.

The guy's story was clearly ludicrous. He claimed he was livid at the way I drove redlining in in every gear from cold (so that's 160mph on some local roads near his house), but didn't say a word when we were driving and then chatted casually to me in his kitchen for 30 mins afterwards. 

I've been invited to drive an awful lot of cars over the years. You'll find an index of some here at the bottom of the main post:

https://www.pistonheads.com/gassing/topic.asp?h=0&f=48&t=1742779

Many of them have offered me multiple drives in their cars. I don't say that to show off, but to provide a counter point to a single fool and his nasty little henchmen, like you. But feel free to explain in text here exactly how you think I treated that guy's car.

I doubt you will, because like all of your sort, you'll be a coward, too.

Edited by Pothole

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Well that went bad quickly! 

I used to get 20-23mpg on average

As high as 30 on the faster roads... Wow

 

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1 minute ago, toplad said:

Well that went bad quickly! 

I used to get 20-23mpg on average

As high as 30 on the faster roads... Wow

 

I know....I have had a quiet look back at his posts and all seem to end up into sl*gging matches and arguments.

I dont know the chap so wont say much more but his history seems to show he does love a good ruck on the internet :(

 

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10 hours ago, Pothole said:

I've been invited to drive an awful lot of cars over the years. You'll find an index of some here at the bottom of the main post:

https://www.pistonheads.com/gassing/topic.asp?h=0&f=48&t=1742779

Many of them have offered me multiple drives in their cars. I don't say that to show off

Are you cmoose on that post as i know theres a pothole on PH too but he doesn't own Porker.

I’m genuinely more interested in how you get offered to drive everyone else's cars

Apologies if i don't know you or what you do for a living, are you a road tester? Magazine writer etc?

I class myself as a decent and confident driver but no one has ever offered me their car other than a salesman 😂 maybe i just don't have any friends 

Edited by r1flyguy

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11 hours ago, Pothole said:

Why is that, then? Very cheap shot, but not a huge surprise coming from you.

The guy's story was clearly ludicrous. He claimed he was livid at the way I drove redlining in in every gear from cold (so that's 160mph on some local roads near his house), but didn't say a word when we were driving and then chatted casually to me in his kitchen for 30 mins afterwards. 

'Clearly' your figures speak for themselves.  One person's idea of overstressing an engine is different to another's.

I like cheap. :)

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Having a look at older threads to see what is the norm for a 3.4 987.1 as plan on taking it to Spain in a few months. Sat at 80ish and a bit of town driving last night it did this. Car is on 46k if that matters - I was quite impressed to be honest.

 

https://ibb.co/Wf0wD91

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1 minute ago, SiBerty said:

Having a look at older threads to see what is the norm for a 3.4 987.1 as plan on taking it to Spain in a few months. Sat at 80ish and a bit of town driving last night it did this. Car is on 46k if that matters - I was quite impressed to be honest.

 

https://ibb.co/Wf0wD91

Real world you will see 23-26mpg when calculated properly....dont rely on the OBC they are always out.

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1 minute ago, Nick_McUK said:

Real world you will see 23-26mpg when calculated properly....dont rely on the OBC they are always out.

I'm sure, the speedo is 3 mph out according to google maps speed too. Even so  I am quite impressed - bearing in mind with I am near Sheffield and its not very flat.

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1 minute ago, SiBerty said:

I'm sure, the speedo is 3 mph out according to google maps speed too. Even so  I am quite impressed - bearing in mind with I am near Sheffield and its not very flat.

Yeah most cars are actually all 3 of ours an thats a BMW 5 Series, a Peugeot 208GTI and the Boxster

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32 minutes ago, Nick_McUK said:

Real world you will see 23-26mpg when calculated properly....dont rely on the OBC they are always out.

Really? I checked mine over several tanks and it was as near as dammit spot on. As I would expect it to be. But of course much more difficult to check if the odometer is accurate.

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30 minutes ago, Nick_McUK said:

Yeah most cars are actually all 3 of ours an thats a BMW 5 Series, a Peugeot 208GTI and the Boxster

They were making cars with accurate speedos 60 and more years ago. When they were purely mechanical. Should be a very simple matter to do that with modern pulse counting types. Yet so many makers continue to design them to over read by the legal maximum.

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Is it not the potential for difference in the diameter of the tyre that means that there needs to be a tolerance? Tyre size, tread, inflation, even the depth of rubber and the grade of that rubber (how much it compresses, etc) could mean that there will be a difference in the circumference of the tyre per revolution for the sensor, whether mechanical or electronic. Might not seem like a lot, but multiply it up by the speed of revolution...

I've always assumed that's the case anyway. Feel free to tell me if I'm wrong.

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I think to get an accurate figure for consumption you could just back-calculate fro emissions. 
 

 

;) 

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On 6/11/2019 at 1:48 AM, Pothole said:

Realistically, cannot possibly be driving it 'hard' getting well over 300 miles from a tank. 360 miles works out to an average of 25mpg. You'd have to drive pretty carefully to achieve that as a long term average. 

I averaged 16mpg over 70,000 miles in the 987.1 3.4 and have averaged 18mpg over 10k miles in my current 987.1 3.2, so have a pretty good feel for what sort of range you get driving these 987 cars hard. That's about 225 and 250 miles range respectively. Like I said, if you're well over 300 miles, that's fairly gentle driving in the context of the type of car we're talking about.

Your numbers mirror my range. I get an average of 25-26mpg and about 350 miles in total out of a tank.

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6 hours ago, Rob™ said:

Is it not the potential for difference in the diameter of the tyre that means that there needs to be a tolerance? Tyre size, tread, inflation, even the depth of rubber and the grade of that rubber (how much it compresses, etc) could mean that there will be a difference in the circumference of the tyre per revolution for the sensor, whether mechanical or electronic. Might not seem like a lot, but multiply it up by the speed of revolution...

I've always assumed that's the case anyway. Feel free to tell me if I'm wrong.

From my understanding & experience its mainly dictated by a combination of a particular market's regulation & tolerances within the system. This includes some of the things you said but also tolerance of the measurement hardware itself. regulations typically say you cannot under read but over reading within a certain amount is allowed.

Some manufacturers then choose to be more conservative than others hence why all brands are not the same.

Edited by naim22

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17 hours ago, DaveEFI said:

They were making cars with accurate speedos 60 and more years ago. When they were purely mechanical. Should be a very simple matter to do that with modern pulse counting types. Yet so many makers continue to design them to over read by the legal maximum.

The speed limit tolerance is MPH +10% +2-3mph.

I think the variance is simply down to the fact that the same car in different trim levels can have anything from a 17" to 20" rim. Plus also it allows for the speedo to read relatively accurately when the tyres are at the end of their serviceable life as the overall Rolling radius does change.

I have noticed though at up-to about 35-40 on all my cars that the speedos are much more accurate...this is taking the GPS speed reading from he Snooper 4Zero radar detectors (have 3 of the same model one in each car)

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18 hours ago, DaveEFI said:

much more difficult to check if the odometer is accurate.

I'm not really interested in the fuel consumption on mine, I don't do enough miles to worry about it (I work from home, so no daily commute for me).  However, I did check the accuracy of the digital speedo against a sat nav the other day, and at 60mph it was only 1 mph out, so I thought that was pretty impressive.

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18 hours ago, Rob™ said:

Is it not the potential for difference in the diameter of the tyre that means that there needs to be a tolerance? Tyre size, tread, inflation, even the depth of rubber and the grade of that rubber (how much it compresses, etc) could mean that there will be a difference in the circumference of the tyre per revolution for the sensor, whether mechanical or electronic. Might not seem like a lot, but multiply it up by the speed of revolution...

I've always assumed that's the case anyway. Feel free to tell me if I'm wrong.

Assuming you have standard tyres, any wear on them will make the speedo read high. So no need to allow for that in the design, since the legal requirement is never to read low. And new to worn out only makes less than 1% difference anyway.

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Comparing GPS data... does this speed take into account changes in elevation? Civil GPS isn't *that* accurate anyway...  

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1 hour ago, Davey P said:

I'm not really interested in the fuel consumption on mine, I don't do enough miles to worry about it (I work from home, so no daily commute for me).  However, I did check the accuracy of the digital speedo against a sat nav the other day, and at 60mph it was only 1 mph out, so I thought that was pretty impressive.

I do mainly short trips and use daily.26 mpg is what I get from my 2006 2.7.Think you may do better with your 2007 having the newer engine..

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