Newbie E89 Odd roof problem

Chippie · Post by **Chippie** » Thu Apr 07, 2022 10:03 pm

Glad you got it sorted, thanks for sharing

flybobbie · Post by **flybobbie** » Fri Apr 08, 2022 8:41 am

Cut the old switch open, see if it's corrosion or loose resistors.
Be interesting to know.

MeonZ · Post by **MeonZ** » Tue Apr 12, 2022 1:33 pm

Sorry flyrobbie, the old one went straight to the big pile of switches in the sky, so I cant help with opening it up i'm afraid.

On a more positive note though, we did 650 miles to Lands End and back on the B-roads over the weekend, roof down the whole way, only putting it up at coffee stops and overnight, and i'm happy to report zero issues, no warning bongs of any kind (other than fuel...

)

Out of interest, we averaged 31mpg for the whole 650 miles, mixture of A303, A30 and the twisty back roads across Cornwall, that sound about right to people? I have the N52 2.5 in mine. Manual box, on 19's

Smartbear · Post by **Smartbear** » Tue Apr 12, 2022 1:52 pm

MeonZ wrote: ↑Tue Apr 12, 2022 1:33 pm Sorry flyrobbie, the old one went straight to the big pile of switches in the sky, so I cant help with opening it up i'm afraid.

On a more positive note though, we did 650 miles to Lands End and back on the B-roads over the weekend, roof down the whole way, only putting it up at coffee stops and overnight, and i'm happy to report zero issues, no warning bongs of any kind (other than fuel... )

Out of interest, we averaged 31mpg for the whole 650 miles, mixture of A303, A30 and the twisty back roads across Cornwall, that sound about right to people? I have the N52 2.5 in mine. Manual box, on 19's

I’d expect more than that if i was just cruising, were you driving quickly?
Rob

MeonZ · Post by **MeonZ** » Tue Apr 12, 2022 2:04 pm

Hmmm, quickly-ish.

All of the dual carriageway sections were 70-80. I was in sport almost the whole journey, probably guilty of enjoying the twisty roads down there...

I think average speed was 37mph for the trip. Just normal day to day driving in and out of Winchester or Southampton I tend to get about 28-29mpg.

That was with the roof down, and the car is on P-Zero runflats.

clarker63 · Post by **clarker63** » Tue Apr 12, 2022 3:18 pm

MeonZ wrote: ↑Tue Apr 12, 2022 1:33 pm Out of interest, we averaged 31mpg for the whole 650 miles, mixture of A303, A30 and the twisty back roads across Cornwall, that sound about right to people? I have the N52 2.5 in mine. Manual box, on 19's

Yes on my old 2.5, I got similar MPG. nowhere near as good as the 2.0 4 pots I'm led to believe

Ole gits rule · Post by **Ole gits rule** » Tue Apr 12, 2022 3:24 pm

Smartbear wrote: ↑Tue Apr 12, 2022 1:52 pm
MeonZ wrote: ↑Tue Apr 12, 2022 1:33 pm Sorry flyrobbie, the old one went straight to the big pile of switches in the sky, so I cant help with opening it up i'm afraid.

On a more positive note though, we did 650 miles to Lands End and back on the B-roads over the weekend, roof down the whole way, only putting it up at coffee stops and overnight, and i'm happy to report zero issues, no warning bongs of any kind (other than fuel... )

Out of interest, we averaged 31mpg for the whole 650 miles, mixture of A303, A30 and the twisty back roads across Cornwall, that sound about right to people? I have the N52 2.5 in mine. Manual box, on 19's
I’d expect more than that if i was just cruising, were you driving quickly?
Rob

I can achieve low 40 on a decent run - 70 to 75 and high 20's around town.

I have done around 550 miles in 18 months with an average of 34 to 35 easily

MeonZ · Post by **MeonZ** » Tue Apr 12, 2022 4:35 pm

Hmmmm,

I wonder why the difference? Do you have any kind of upgrades to the air filter and so on?

What tyres are you on? I'm not expecting anything amazing, but on the motorway at 75, I was hoping for mid-30's to be honest...

clarker63 · Post by **clarker63** » Tue Apr 12, 2022 4:59 pm

MeonZ wrote: ↑Tue Apr 12, 2022 4:35 pm Hmmmm,

I wonder why the difference? Do you have any kind of upgrades to the air filter and so on?

What tyres are you on? I'm not expecting anything amazing, but on the motorway at 75, I was hoping for mid-30's to be honest...

Mine was completely standard and I never got anywhere near what Ole gits rule says. I am not a particularly heavy footed driver.

https://www.honestjohn.co.uk/realmpg/bmw/z4-2009

this suggests around 30, which is what you and I got... and confirms that the 2.0 based ones get better MPG.

MeonZ · Post by **MeonZ** » Tue Apr 12, 2022 5:05 pm

37 real world from the S-drive 28i?? - Looks like i'll be changing the inlet manifold then....

Smartbear · Post by **Smartbear** » Tue Apr 12, 2022 7:43 pm

MeonZ wrote: ↑Tue Apr 12, 2022 5:05 pm 37 real world from the S-drive 28i?? - Looks like i'll be changing the inlet manifold then....

I drove down to Cornwall a couple of weeks ago, 70/80mph on the main roads - computer said this (over 520miles range)

: 81B7D0DB-2FE5-422D-8AB3-B51EA45EFD6E.jpeg (119.66 KiB) Viewed 311 times

Rob

Ole gits rule · Post by **Ole gits rule** » Tue Apr 12, 2022 7:59 pm

clarker63 wrote: ↑Tue Apr 12, 2022 4:59 pm
MeonZ wrote: ↑Tue Apr 12, 2022 4:35 pm Hmmmm,

I wonder why the difference? Do you have any kind of upgrades to the air filter and so on?

What tyres are you on? I'm not expecting anything amazing, but on the motorway at 75, I was hoping for mid-30's to be honest...
Mine was completely standard and I never got anywhere near what Ole gits rule says. I am not a particularly heavy footed driver.

https://www.honestjohn.co.uk/realmpg/bmw/z4-2009

this suggests around 30, which is what you and I got... and confirms that the 2.0 based ones get better MPG.

I have actually tracked the fuel usage each time I fill cos I'm a sado and when I bought the car was £4.76 a gallon and last fill up was £7.35 and average mpg is 34.98 with a reasonable mixture of roads.

I am light footed in reality but can make the car move if needed.

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