997.2 Fuel Economy
Discussion
sanjoyp said:
Hmm I am 1 month into 997 GTS ownership and am concerned about my mpg. 50:50 motorway and country roads and I am getting 16.5mpg. Thats using the Road Trip app and the odometer readings rather than the onboard which is showing slightly higher.
When OPC handed over the car they advised to use normal fuel no need for super. Thoughts? Run it dry then run a tank of super as per the above? Call it in to OPC and let them deal with it?
TIA
S
Seems awfully low even for a 4GTS. I'd put nothing but super in mine and had the same 'advice' from the OPC. Would personally try super first, stick it on cruise at 70 and you should see low 30's. If not, I'd speak to OPC. When OPC handed over the car they advised to use normal fuel no need for super. Thoughts? Run it dry then run a tank of super as per the above? Call it in to OPC and let them deal with it?
TIA
S
GT4 said:
You CAN run on 95, but don't.
As we are talking 997, the 997.2 DFI really hates 95 (the 997.1 less so)
But the manual and fuel flap say 98 RON, and for good reason.
Not only do you lose power, but that cheaper fuel is used quicker.
The engine will run hotter too on 95 RON, and that is not good for all sorts of longevity, thermal stress and reliability reasons.
Expect to lose about 30BHP and a load of torque if you use 95 RON fuel on a Turbo (less so on an NA, but still more than 10 BHP).
95 RON will also result in increased consumption at a steady speed - by up to 2-3mpg (so an easy 10%).
So a real false economy to fill with the cheap stuff.
The DME can "learn" the fuel grade (and atmospheric fuelling effects), so if you are planning on using a higher grade than in the last tankful, do a reset for immediate effect (rather than waiting for up to half a tank to passive reset).
DME reset is via key, Throttle Body reset is via key
Reset via key requires turning the key to ignition "1" (the position when all the lights are on on the dash) and leaving it for 60+ secs (DO NOT TOUCH THE THROTTLE PEDAL), then switch off for 10+ secs and you should be able to hear a few clicks and whirs from the engine bay as it recalibrates the adaption values.
Adaption must be performed when ambient temps are > 10°C
http://www.911uk.com/viewtopic.php?p=883412&sid=e26b0fa1c2bb715b35e4c531d43d54c2As we are talking 997, the 997.2 DFI really hates 95 (the 997.1 less so)
But the manual and fuel flap say 98 RON, and for good reason.
Not only do you lose power, but that cheaper fuel is used quicker.
The engine will run hotter too on 95 RON, and that is not good for all sorts of longevity, thermal stress and reliability reasons.
Expect to lose about 30BHP and a load of torque if you use 95 RON fuel on a Turbo (less so on an NA, but still more than 10 BHP).
95 RON will also result in increased consumption at a steady speed - by up to 2-3mpg (so an easy 10%).
So a real false economy to fill with the cheap stuff.
The DME can "learn" the fuel grade (and atmospheric fuelling effects), so if you are planning on using a higher grade than in the last tankful, do a reset for immediate effect (rather than waiting for up to half a tank to passive reset).
DME reset is via key, Throttle Body reset is via key
Reset via key requires turning the key to ignition "1" (the position when all the lights are on on the dash) and leaving it for 60+ secs (DO NOT TOUCH THE THROTTLE PEDAL), then switch off for 10+ secs and you should be able to hear a few clicks and whirs from the engine bay as it recalibrates the adaption values.
Adaption must be performed when ambient temps are > 10°C
GT4P said:
Another thing to add to the above is where you buy your fuel I notice about 5-8% difference on our 1.2 fiesta between say a well known supermarket and Esso!
I only use shells finest in my pork and will drive out of my way to fill up!
Agreed - 95 is a false economy. I use Tesco Momentum, as bizarrely seem to get better performance with that over Shell. Either way, anything but 95 is the point here. I only use shells finest in my pork and will drive out of my way to fill up!
It always amazes me that some people will buy a £30, £40, £50k plus car, and put cheap fuel in... Bonkers!
My E46 M3 only ever has Shell's finest, as will my Porsche when I get it!
High performance engines are designed to run on the stuff. Anyone skimping on decent fuel is probably skimping on other stuff too...
My E46 M3 only ever has Shell's finest, as will my Porsche when I get it!
High performance engines are designed to run on the stuff. Anyone skimping on decent fuel is probably skimping on other stuff too...
sanjoyp said:
Will give it a shot and report back.
S
So a couple of months have gone by. Have used 97, Sell V-Power Nitro and finally Tesco 99. 99 has given me the best result which is still sub 20 for a tank.S
I went to the dealer (45 min drive away) who check tyre pressures and got it up on ramps to check brakes were not binding. All checked out fine. He then took it out and put it on cruise at 60 etc and said he returned in the 20s which I have never seen. I then showed him my output from my Road Trip app (below), 15.64-18.19 mpg. He initially stated that you have a 3.8l flat 6 Sir, my mates GT3 beats that mpg on track and I'd rather not spend so much time seeking out 99. "Dont use 99, no point standard fuel is fine".
He said he has his guy reset / re-calibrate the fly by wire throttle and that the only change he made.
Bottom line is he says there is nothing he can do with out holding on to the car for longer time as there are no error codes and when he drove it (hot) it was returning 20s. "Keep an eye on it and report back". Hacked off.
I was then at a charity track day the following day talking to a friend who has a V10 R8 who had similar problems. He solved them by taking it out on track and spanking it. Essentially saying that the the engine was coked up and prolonged open throttle cleared it. I took it out for 10 laps and am off to fill it up tonight. Previous owner was in SW1 so perhaps its had an easy life pottling around London and is coked up? Anyone ever ran some form of Redex through their car?
S
Hmm....Have you considered having a 'Hydrogen clean'? My business partner runs a dfi Cayenne S, he had a guy treat his motor with this system, it showed a 10% increase in mpg.
Dfi engines have zero fuel going through the intake ports to keep them clean, hence they block with gunk. Google the phenomenon, they look truly horrendous in a relatively short time. The 'cleaning' cost around a hundred quid and made a significant difference to his 72k miles car, he noted that after the treatment it felt like the sport button was on when it was off. Cleaning the intake ports means that the engine is taking in the proper amount of air to match the theoretical fuel input. A maf sensor only knows the global air consumption rather than cylinder specific.
I realise this may not be everyones cup of tea, but as a very sceptical person, I was impressed. No affiliation, I can't even remember the company name. It did work though. The experience of seeing this has not put me off a buying a 997.2 if and when I decide to change my 996 turbo.
Dfi engines have zero fuel going through the intake ports to keep them clean, hence they block with gunk. Google the phenomenon, they look truly horrendous in a relatively short time. The 'cleaning' cost around a hundred quid and made a significant difference to his 72k miles car, he noted that after the treatment it felt like the sport button was on when it was off. Cleaning the intake ports means that the engine is taking in the proper amount of air to match the theoretical fuel input. A maf sensor only knows the global air consumption rather than cylinder specific.
I realise this may not be everyones cup of tea, but as a very sceptical person, I was impressed. No affiliation, I can't even remember the company name. It did work though. The experience of seeing this has not put me off a buying a 997.2 if and when I decide to change my 996 turbo.
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