Struggling to find the right E89…. 35is real world MPG?

[True-Blue]

I’ve been trying to find the right E89 for the other half for a little while now, she knows what colours she wants and she wants IDRIVE… which immediately decimates the available options.

I’m starting to think a 35is wouldn’t be the worst idea in the world ever….

This would be her daily driver, and she only does around 6k miles per year (often less)

So question 1, what’s the real world mpg for a 35is… she’s not heavy footed at all.

I think this might be a bad idea because she wants ‘reliable’ above performance… but I’ve seen a few very nice looking 35is pop up and they’re distracting me

[Jollyjoiner]

Well I have a stage 1 mapped 35i and have a heavy right foot and seem to be getting around 24mpg. A couple of years ago we had a 750mile round trip to Cornwall and I drove at 70 with cruise on nearly all the time and managed 41mpg at the end of the weekend

[True-Blue]

That’s sounds decent bearing in mind the performance, maybe I’ll focus her on the higher end of that range

She’s one of those who puts £15 or £20 in at a time, does my nut in as it’s not that she can’t afford it… makes no sense at all, old habits die hard and all that

[B21]

Like most later turbo ICE cars..the fuel consumption is non linear relative to how much throttle..

Heavy use of throttle results in disproportionate increase in fuel consumption as the ecu richens up the mixture as throttle position increases.

The 'problem' is that using a lot of throttle is 'easy' with a turbo as it makes power everywhere..unlike a NA ICE where peak power and torque only appear much higher up the rev range.

So if you pussy foot around or road conditions restrict your ability to press the throttle a turbo car CAN be as or more econimical as a NA car.

Having said all that..with over 50 group runs over 7 years and some 100-150 tank refills of anywhere between 4 and 12 cars the difference on a run where everybody was more or less following each other at the same pace resulted typically in 2-4 litres different in 45 litres between 23i and 35is.

I like the logic that there is a more plentiful supply of 35is with idrive than all other E89s put together....


FWIW I average around 28 mpg with my type of driving..cruising on a motorway at 80 ish I see 33 mpg-36 mpg

[N4LLY]

I am the same as your Mrs. Put £ 25.-- in each time. This used to be the ammount used for a weeks commute.
back in the day.
Only time i noticed an MPG in a car was an old 730i at 16 MPG when petrol prices maxed out.

Even now, only reset MPG when about to venture on a long motorway journey. Rare now a days.

Have never purchased or concidered based on MPG, to me that is just nuts.

[matsmith749]

35is is the right answer everytime

Around town 30mph stop start, heavy traffic - think 18mpg
Around town 30mph (mix of some 40mph) normal traffic - think 22mpg
Faster roads 40mph - 50mph with normal traffic - think 27mpg
Motorway >20 miles - think 38mpg
Really long motorway trip >100 miles - 41 mpg (my best ever)

Mrs is welcome to come have a play in mine (so longa as she likes mineral white).

[enuff_zed]

B21, is it still necessary with modern turbos to let them wind down (engine at idle) for a little while before you switch off?
I always do as a matter of course anyway.
I'm thinking a lack of mechanical sympathy could cost more than a low mpg.

[B21]

B21, is it still necessary with modern turbos to let them wind down (engine at idle) for a little while before you switch off?
I always do as a matter of course anyway.
I'm thinking a lack of mechanical sympathy could cost more than a low mpg.

Officially no….the ECU continues to circulate coolant through the turbos after engine shut down for a period of time to avoid oil coking..

Personally I always have a 2 minute ish period of steady ie slow barely above rock over driving then at least 30 seconds of idle before shutdown...

If I haven’t had that then I leave it on idle for at least a minute..

[enuff_zed]

B21, is it still necessary with modern turbos to let them wind down (engine at idle) for a little while before you switch off?
I always do as a matter of course anyway.
I'm thinking a lack of mechanical sympathy could cost more than a low mpg.

Officially no….the ECU continues to circulate coolant through the turbos after engine shut down for a period of time to avoid oil coking..

Personally I always have a 2 minute ish period of steady ie slow barely above rock over driving then at least 30 seconds of idle before shutdown...

If I haven’t had that then I leave it on idle for at least a minute..

Cheers.
I know there is only the smallest film of oil supporting a shaft spinning at ludicrous speeds and in the old days, when the engine stopped, so did the oil pump, leaving the shaft to bottom out in its bearing.

[Marcoose]

So question 1, what’s the real world mpg for a 35is… she’s not heavy footed at all.

He (or she) considering a 6-cyl, bi-turbo, 335bhp sportscar whilst concerned by MPG (and tyres, oil changes, coils, etc) is considering the wrong car.

Just buy it. Happy wife, happy life.

[B21]

B21, is it still necessary with modern turbos to let them wind down (engine at idle) for a little while before you switch off?
I always do as a matter of course anyway.
I'm thinking a lack of mechanical sympathy could cost more than a low mpg.

Officially no….the ECU continues to circulate coolant through the turbos after engine shut down for a period of time to avoid oil coking..

Personally I always have a 2 minute ish period of steady ie slow barely above rock over driving then at least 30 seconds of idle before shutdown...

If I haven’t had that then I leave it on idle for at least a minute..

Cheers.
I know there is only the smallest film of oil supporting a shaft spinning at ludicrous speeds and in the old days, when the engine stopped, so did the oil pump, leaving the shaft to bottom out in its bearing.

Yes quite so…I suspect when they made the move from turbos for caring / discerning motorists to the great unwashed they had to do something otherwise there would be 100,000s of warranty claims..the JDM boys had their nice turbo countdown timers..

On our turbo’d aircraft we sat a countdown timer..earlier ones had 2 minutes and later a minute..given that by that stage they had only be taxiing on idle power for several minutes it seemed prudent..it was mandated in the AFM..

[flybobbie]

Officially no….the ECU continues to circulate coolant through the turbos after engine shut down for a period of time to avoid oil coking..

Personally I always have a 2 minute ish period of steady ie slow barely above rock over driving then at least 30 seconds of idle before shutdown...

If I haven’t had that then I leave it on idle for at least a minute..

Cheers.
I know there is only the smallest film of oil supporting a shaft spinning at ludicrous speeds and in the old days, when the engine stopped, so did the oil pump, leaving the shaft to bottom out in its bearing.

Yes quite so…I suspect when they made the move from turbos for caring / discerning motorists to the great unwashed they had to do something otherwise there would be 100,000s of warranty claims..the JDM boys had their nice turbo countdown timers..

On our turbo’d aircraft we sat a countdown timer..earlier ones had 2 minutes and later a minute..given that by that stage they had only be taxiing on idle power for several minutes it seemed prudent..it was mandated in the AFM..

Also on Seneca turbo set rpm to 1500 after start. Do you see that on turbo cars? Or do they idle 600rpm.

[B21]

Cheers.
I know there is only the smallest film of oil supporting a shaft spinning at ludicrous speeds and in the old days, when the engine stopped, so did the oil pump, leaving the shaft to bottom out in its bearing.

Yes quite so…I suspect when they made the move from turbos for caring / discerning motorists to the great unwashed they had to do something otherwise there would be 100,000s of warranty claims..the JDM boys had their nice turbo countdown timers..

On our turbo’d aircraft we sat a countdown timer..earlier ones had 2 minutes and later a minute..given that by that stage they had only be taxiing on idle power for several minutes it seemed prudent..it was mandated in the AFM..

Also on Seneca turbo set rpm to 1500 after start. Do you see that on turbo cars? Or do they idle 600rpm.

Ours had something similar ..the aim was to get the oil up to a certain temp before applying 100% load..

[mcbutler]

its not the cost of fuel you need to worry about with a 35.....

[matsmith749]

Bears beats battlestar galactica