N52 3L mpg
- Thread starter Theog
- Start date
oke:Scooba_Steve said:Anticipation and smoothness
Lower revs don't equal lower fuel consumption, you want the car running at the lowest RPM but still in the torque band. All other things being equal fuel consumption is proportional to throttle opening. Too high a gear and you need more throttle for the same speed.
Very interesting. I always wondered about this.
If you put your foot down in 6th at low revs (i dont but just as an example), does this flood the engine, or does it get burnt? Or is the fuel limited into the engine but still more is used to raise speed than using gears correctly? Ive heard a few myths around you see.
Im still getting used to the right amount of revs / throttle / gear as have been driving a diesel my whole life.
Steve84N said:
Just because it manages doesn't mean it's a good idea.
Max torque is between 2500 and 4250 rpm. So all other things being equal you will have a wider throttle opening at 1300 rpm than 2500 for the same speed. This will be greater still when going uphill.
It's also somewhat pointless being in 6th at 30 as you have reduced acceleration potential.
I too don't achieve the higher figures quoted here.
My Zed is for enjoyment and so the driving style will be different to that of a daily.
Only had 38mpg once on a long steady constant drive on the motorway at speed limit +10percent.
With 6 cylinders every time you open her up its going to eat fuel.
26.6mpg average on our runs but can drop a lot lower when pressing on.
Still very useful mpg given the performance.
My Zed is for enjoyment and so the driving style will be different to that of a daily.
Only had 38mpg once on a long steady constant drive on the motorway at speed limit +10percent.
With 6 cylinders every time you open her up its going to eat fuel.
26.6mpg average on our runs but can drop a lot lower when pressing on.
Still very useful mpg given the performance.
7 mile drive to work and then back again seems to net me about 250 miles per tank give or take (probably low 20s).
Long drive up to the Glasgow office at 70 - 80 indicated gets an indicated 38 MPG.
Mine is an auto though so probably not as good on juice as a manual.
Any other driving action is generally hoonage, so my overall average is probably quite low!
I wouldn't be labouring the engine by doing 30 mph in 6th either. I find 4th gear the sweet spot at 30.
Long drive up to the Glasgow office at 70 - 80 indicated gets an indicated 38 MPG.
Mine is an auto though so probably not as good on juice as a manual.
Any other driving action is generally hoonage, so my overall average is probably quite low!
I wouldn't be labouring the engine by doing 30 mph in 6th either. I find 4th gear the sweet spot at 30.
My average is about 27mpg....5 miles to work everyday and a blast at the weekend. No idea how people are averaging in the 30s?!
All else is not equal. Max torque requires more fuel than the required torque to propel you along at 30mph.Scooba_Steve said:
1,300rpm is plenty to provide enough torque to do 30mph on a flat. It'll be making well over 100lb/ft and probably at least 40-50bhp plus it idles just fine at 6-700rpm. If you drive the same piece of road at 30mph and reset the mpg trip computer at the same point each time then doing it in 6th compared to 4th I bet you will use less fuel. I'm well aware of feeling when the engine is labouring and I will drop down before that happens. I don't need more acceleration potential when I'm just following someone else. I would say it's pointless making more power than you need to and reduced acceleration potential is only pointless when you want acceleration.
With a smaller engine you do need more of its potential more of the time to maintain a speed but when you have an engine that is capable of producing much more power than is needed to maintain normal speeds why bother burning more fuel than you need to? Saves more for when you do want to accelerate...
To answer the original question I get around 31-32mpg on a 26 mile commute to work each way which is a mix of about a third A-Roads with overtakes, third motorway at 80mph and third city driving/traffic.
Well you have to concentrate on one variable at a time. If you're in 6th you're actually reducing the torque to the wheels as it's an overdrive ratio of 0.85. How is that not wasting power?
3rd and 4th at 30 provide the most flexibility and control. Though I would happily wager that any savings from gear selection are well offset by poor planning and anticipation.
3rd and 4th at 30 provide the most flexibility and control. Though I would happily wager that any savings from gear selection are well offset by poor planning and anticipation.
Steve84N said:
I take your point Steve but wonder if driving the Zed in this way can be harmful to the engine and transmission and lead to problems? (for example placing the engine under load at low speeds when commuting? Might low rev use contribute to the dreaded VANOS woes?)
I'm often amazed how my Zed seems to shrug off spirited use, revving in the sweet spot and 'making progress'. We do many miles each year (12000) driving for pleasure in our Zed. Every time I park up I'm amazed by the Zed. Coming back from a 1000 miles and 5 days of incredible roads and 'making progress' mostly in 2nd 3rd and 4th, I parked the filthy Zed up and the very next day needed it to pick up my daughter. It fired on the button and ticked over smoothly, acceleration was strong and all controls tight and responsive - like it had faced nothing! It's an amazing machine and how it shrugs off and manages such use with such long service intervals astounds me (though I do include an extra oil service to be fair, between major servicing). I believe that using my Zed in this way and keeping it well maintained is best for the machine - it certainly seems to thrive on it
.paulgs1000 said:. . . .
I'm often amazed how my Zed seems to shrug off spirited use, revving in the sweet spot and 'making progress'. We do many miles each year (12000) driving for pleasure in our Zed. Every time I park up I'm amazed by the Zed. Coming back from a 1000 miles and 5 days of incredible roads and 'making progress' mostly in 2nd 3rd and 4th, I parked the filthy Zed up and the very next day needed it to pick up my daughter. It fired on the button and ticked over smoothly, acceleration was strong and all controls tight and responsive - like it had faced nothing! It's an amazing machine and how it shrugs off and manages such use with such long service intervals astounds me (though I do include an extra oil service to be fair, between major servicing). I believe that using my Zed in this way and keeping it well maintained is best for the machine - it certainly seems to thrive on it
I can relate to this Paul. I always wanted a car that was, for want of a better word, 'overpowered'. And having a 3 litre 24 valve N/A engine slotted into a lightweight 2 seater roadster seems to give me that. The car always has lots more in reserve, you'd have to have a track to yourself to be driving it at its limit for prolonged periods of time. And so you're right - the day after a week of spirited driving, you turn the key and it growls into life and sets off like it's just a had a week resting in the garage
Everyone knows that more revs equals more fuel used which is why you don't drive around in 2nd gear. It's why you change up to top gear on the motorway. It's why Porsche put a stupidly long 7th gear on their cars and any automatic gearbox now changes up as fast as possible to top gear to reduce fuel consumption.Scooba_Steve said:
You can feel that your foot is applying more throttle at 30 in 3rd than in 6th so how is a lower gear a smaller opening?
Yes it's an overdrive gear but it keeps the revs down which is why it's more fuel efficient.
My car does not suffer from cruising in higher gears and gets plenty of exercise to the upper reaches.
I'll do a test over the next few days as I suggested...
thecremeegg said:
Hi, your lowish average could be caused by your short commuting distance, the engine will have barely got up to full operating temperature before its turned off again-it runs richer whilst its still getting up to temp & this isn't good for economy
rob
paulgs1000 said:Steve84N said:
I take your point Paul but wonder if driving the Zed in this way can be harmful to the engine and transmission and lead to problems? (for example placing the engine under load at low speeds when commuting? Might low rev use contribute to the dreaded VANOS woes?)
I'm often amazed how my Zed seems to shrug off spirited use, revving in the sweet spot and 'making progress'. We do many miles each year (12000) driving for pleasure in our Zed. Every time I park up I'm amazed by the Zed. Coming back from a 1000 miles and 5 days of incredible roads and 'making progress' mostly in 2nd 3rd and 4th, I parked the filthy Zed up and the very next day needed it to pick up my daughter. It fired on the button and ticked over smoothly, acceleration was strong and all controls tight and responsive - like it had faced nothing! It's an amazing machine and how it shrugs off and manages such use with such long service intervals astounds me (though I do include an extra oil service to be fair, between major servicing). I believe that using my Zed in this way and keeping it well maintained is best for the machine - it certainly seems to thrive on it
Hi Paul, I see your concerns but as long as the driver has some mechanical sympathy & doesn't put the engine under high load (ie-foot down hard at 30mph in sixth) then normal commuting wont harm it.
Its the same for the vanos system, what's more likely to help isn't the style of driving but the maintenance regime-increasing the oil change frequency is going to do more for its health than a good leathering 8)
Rob
