How to improve Fuel Efficiency (E89 20i)
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weegeoff said:Silly me I thought it was because cold air was denser than warm air. Thus helping with fuel economy
Assuming the car's ecu is using the AF ratio to adjust the fuel mixture then no, colder more dense air would = more fuel to maintain the same AF mixture (usually around 14.7:1). I used to love my Evo on freezing cold days the extra fuel with the extra cold air was fantastic and quite noticeable
Its entirely possible to run a turbo without a IC assuming you're keeping the boost down very low, reliability is obviously at risk though.
Mister T said:
This is true all will do pretty much the same mileage. Even the older 6 pots won't be that much worse in real world driving. Unless you are doing mega miles a year in monetary terms there won't be a significant difference. On the other hand if you really have to worry about what little difference in costs there is between these engines then should you even be considering a Zed?
I err towards a conservative driving style in order to save fuel but over here in NL it's simply not allowed to cruise up to a red light which is in plain view, otherwise one incurs the wrath of 'the ridiculously impatient typical Dutch driver' who would rather steam up to said light at 50kmh and then jam on the brakes unecessarily.
This particular demographic also frowns upon sticking to the speed limit anywhere if there are no cameras around and has no hesitation in letting you know of his/her disapproval of sticking to the speed limit by tailgating in order to intimidate you into driving faster.
And did I mention that it's perfectly acceptable (to them) to pull out of a junction in front of you at either side of the road in order not to impede their progress?
And woe betide anyone who even thinks about not hammering away from a red light when it turns to green. No such thing as a 'relaxed, controlled accelleration' style exists here it's strictly F1 Murray Walker style 'Go Go Gooooo' orders!
:roll:
This particular demographic also frowns upon sticking to the speed limit anywhere if there are no cameras around and has no hesitation in letting you know of his/her disapproval of sticking to the speed limit by tailgating in order to intimidate you into driving faster.
And did I mention that it's perfectly acceptable (to them) to pull out of a junction in front of you at either side of the road in order not to impede their progress?
And woe betide anyone who even thinks about not hammering away from a red light when it turns to green. No such thing as a 'relaxed, controlled accelleration' style exists here it's strictly F1 Murray Walker style 'Go Go Gooooo' orders!
:roll:
Colder air more power, so use less throttle. And drive on days when the air pressure is high.
Fuel efficient tyres tend to be harder and noisy.
I drove home tonight using the triangle, got 36 mpg. Never went above 45mph.
I thought the later engines had more torque, surely you won't get that without burning more fuel.
And on turbo does air temp. and pressure make any difference.
Good car to have in Austria i suppose.
Fuel efficient tyres tend to be harder and noisy.
I drove home tonight using the triangle, got 36 mpg. Never went above 45mph.
I thought the later engines had more torque, surely you won't get that without burning more fuel.
And on turbo does air temp. and pressure make any difference.
Good car to have in Austria i suppose.
Smartbear said:Silverstar said:
It’s not just fuel savings, the 2litre zeds are cheaper to tax due to lower emissions & servicing is also less expensive.
The op is also after a car younger than the 23/30i models
Rob
You are missing the point of my post, I am just saying if you are that worried about what little difference in running costs there is between these engines then you really ought to be looking elsewhere. Just for the record the tax difference is £105 for the year between the 20i and 30i and how much in service cost? extra 2 litres of oil? ok so you need 6 sparks plugs instead of 4 but they only get changed every 60k miles. Basically you are talking about a difference of around £12 per month which just like the argument for fuel, if that small amounts troubles you then should you be looking at a Zed? As far as I can see the OP hasn't mentioned how old or young a car he wants.
engine killer
Member
by changing the driving style as mentioned, i have managed to improve from 16mpg to 27mpg mostly urban driving, both figures are average of 4 almost full tanks run
Silverstar said:
This, anyone looking to buy a car like a Z4 that is asking questions about how to penny pinch and save money on things like fuel sounds like they are not making a wise decision :idunno:
Whats the point in getting the car if at every turn your first thought is... how much money do I have and can I afford to drive it?
Madness
Silverstar said:Smartbear said:Silverstar said:
It’s not just fuel savings, the 2litre zeds are cheaper to tax due to lower emissions & servicing is also less expensive.
The op is also after a car younger than the 23/30i models
Rob
You are missing the point of my post, I am just saying if you are that worried about what little difference in running costs there is between these engines then you really ought to be looking elsewhere. Just for the record the tax difference is £105 for the year between the 20i and 30i and how much in service cost? extra 2 litres of oil? ok so you need 6 sparks plugs instead of 4 but they only get changed every 60k miles. Basically you are talking about a difference of around £12 per month which just like the argument for fuel, if that small amounts troubles you then should you be looking at a Zed? As far as I can see the OP hasn't mentioned how old or young a car he wants.
The op had previously said he wants a 2015/16 car
Rob
I dont think we should ever discourage someone who has their heart set on a z4 just because they want to drive it a little differently to the rest of us
Smartbear said:
Err no he hasn't, anyway still not the point of what I was saying!
Flyingfifer said:
Why is it madness...? OP has said he wants an E89, he loves the styling. What he’s asking is how to be as efficient as possible WITH an E89, NOT what is a more efficient car to drive. Before making your condescending little quips that you’re getting rather good at in terms of frequency, perhaps understand what is being asked.
john-e89 said:
Its madness because there are concerns around the expense/use of the very thing that makes it useful, unless its just an ornament that's being sought? Why buy a car like this if you will have to worry about whether or not you can use the thing?
You misunderstand, I am not being condescending I am trying to point out that if someone is in a position where they are worrying about the financial cost of fuel then buying something like a Z4 really isnt sensible. Or is your argument that should we be encouraging people to make large purchases of vehicles they love but that will cause them to struggle financially and as such be unable to actually enjoy?
If I have the wrong end of the stick here and what we actually have is someone who wants to use as little fuel as possible for environmental reasons but they are buying a BMW sports car then I will happily STFU :idunno:
Flyingfifer said:
You 100% have the wrong end of the stick yes. OP has never said he’s worried about being able to afford fuel as you say, you’re making an assumption, he’s asking how to be as efficient as possible with an E89, it’s clearly the car he wants. He’s never mentioned environmental issues either. He’s never said he’s worried if he can use an E89 due to cost either. He’s never said he’s struggling financially, you’re assuming again. I’m not encouraging him to buy the car, nobody is, the replies have been answering his questions. Try to understand the question he asked: It’s how to be as efficient as possible with an E89, that’s it, assuming anything about his financial situation is pure speculation. So yes, it seems we have someone that wants a BMW and wants to be as fuel efficient as possible, we don’t know why, but he wants an E89, personally I don’t see anything wrong with this whatsoever, he may enjoy cruising rather than thrashing, he hasn’t said so anything we think is speculation.
john-e89 said:
Well to avoid more assumptions we will just need to wait and see what the OP says :idunno:
Obviously I'm not the only one that has interpreted the question in this way and the OP hasn't said that isn't why the concern is around fuel efficiency in response to those people or myself.
Flyingfifer said:
This is like dragging a mule through knee deep treacle in lead diving boots....
Wait and see what OP says about what...? His financial situation...? Why would he tell us that...? :? Most replies seem to have grasped the question as far as I can see, and replied accordingly, that’s it, done. No need to go off on a tangent that is assumption and speculation imho.
Silverstar said:Smartbear said:Silverstar said:
It’s not just fuel savings, the 2litre zeds are cheaper to tax due to lower emissions & servicing is also less expensive.
The op is also after a car younger than the 23/30i models
Rob
You are missing the point of my post, I am just saying if you are that worried about what little difference in running costs there is between these engines then you really ought to be looking elsewhere. Just for the record the tax difference is £105 for the year between the 20i and 30i and how much in service cost? extra 2 litres of oil? ok so you need 6 sparks plugs instead of 4 but they only get changed every 60k miles. Basically you are talking about a difference of around £12 per month which just like the argument for fuel, if that small amounts troubles you then should you be looking at a Zed? As far as I can see the OP hasn't mentioned how old or young a car he wants.
I think you’re missing the point of the op, there’s nothing wrong with wanting a more fuel efficient car & the 2litre turbo’s are more fuel efficient than the older 6pot models, the additional savings on tax & servicing are just icing on the cake.
To argue that the savings are only small ones is just dancing around on a pinhead, they all contribute to the op’s wish for the most efficient model of z4 he can buy.
Rob