View Full Version : Rear Wheel Arch Gap & The Petrol (Gas) Tank: An Observation
Have you ever noticed the following?
As you may know, my 650i is 100% OEM. Whenever I fill her up full with petrol (gas), the gap between the rear tyres of the car and the rear wheel arches (i.e. body of the car) sit nicely in line with the front wheel arches' gap (or roughly to that effect). The gaps look consistent front & rear. Lately, I’ve noticed than when the petrol tank is less than one quarter filled (i.e. approaching reserves), the rear gap between the tyres and its wheel arches rise more. Obviously, the first thought that comes into mind is the petrol (gas) tank is much lighter and so the car lifts up its rear “naturally”.
Is that what’s happening? I thought there might be some self-balancing mechanism in the suspension (or whatever) that might cancel out the weight differences between a filled and a near empty petrol (gas) tank. I never really took notice of this with the 6er until recently. Have a look next time at yours, to see if you can notice the difference.
I think your car is haunted. I mean, just look at your avatar! Wasn't your car rolled through the "Individual" line on October 31st?
I think your car is haunted. I mean, just look at your avatar! Wasn't your car rolled through the "Individual" line on October 31st?
You're right. There is a ghost in my petrol (gas) tank. It swims in it when filled and vanishes when approaching empty.
P.S. You dislike my Avatar? Let me see if I can find a more civilised one.
I like your avatar but I am always scared when you post. he he
I think your car is haunted. I mean, just look at your avatar! Wasn't your car rolled through the "Individual" line on October 31st?
You're right. There is a ghost in my petrol (gas) tank. It swims in it when filled and vanishes when approaching empty.
P.S. You dislike my Avatar? Let me see if I can find a more civilised one.
Your avatar makes me feel as young as a spring chicken. But I can't seem to cross the road. :old:
By the way, while it's true your car is 100% OEM (of which I am the Viceroy, as you may know), it is also an Individual. Of course, it will soon be outmoded with the MY 2008 refresh. :shut:
By the way, while it's true your car is 100% OEM (of which I am the Viceroy, as you may know), it is also an Individual. Of course, it will soon be outmoded with the MY 2008 refresh. :shut:
I changed my Avatar, for now. Whaddaya think?
Classic BMW Individual from 2006. I like it, until the F-something comes out. Then I'll replace the damn thing.
By the way, we're a bit off topic (only a little bit). :greenlaff:
boxboss
08-01-2007, 06:09 PM
Oz, are you saying it never did that before? I've never paid that much attention to mine. A full tank of gas weighs, what - about 160 lbs? So the difference between a full and a quarter tank would be ~120 lbs. Is that enough to make a noticeable difference in wheel gap? I doubt it...image what a full tank, luggage and 3 passengers would do! Cheaper than lowering springs.
Have you ever noticed the following?
As you may know, my 650i is 100% OEM. Whenever I fill her up full with petrol (gas), the gap between the rear tyres of the car and the rear wheel arches (i.e. body of the car) sit nicely in line with the front wheel arches' gap (or roughly to that effect). The gaps look consistent front & rear. Lately, I’ve noticed than when the petrol tank is less than one quarter filled (i.e. approaching reserves), the rear gap between the tyres and its wheel arches rise more. Obviously, the first thought that comes into mind is the petrol (gas) tank is much lighter and so the car lifts up its rear “naturally”.
Is that what’s happening? I thought there might be some self-balancing mechanism in the suspension (or whatever) that might cancel out the weight differences between a filled and a near empty petrol (gas) tank. I never really took notice of this with the 6er until recently. Have a look next time at yours, to see if you can notice the difference.
You're not crazy, insane nor ghosts are running amok in your gas tank. You have assumed correctly. Your bimmer like my 6er and 7er does the very same thing! :race:
The next time you fill up with petrol press your backside against the car (Lean on it) and you will feel your baby raise itself to become once again the Ultimate Driving Machine! :bravo:
boxboss
08-01-2007, 06:20 PM
You're not crazy, insane nor ghosts are running amok in your gas tank. You have assumed correctly. Your bimmer like my 6er and 7er does the very same thing! :race:
The next time you fill up with petrol press your backside against the car (Lean on it) and you will feel your baby raise itself to become once again the Ultimate Driving Machine! :bravo:
Maybe I'm insane (or just :old:) I didn't know the 6er had a self leveling suspension!
Looks like GMAN has a haunted car, too. When I go to a gas station and fill up, my car laughs at me. And then, like Audrey 2 (in the musical version of "Little Shop of Horrors"). says: feed me; feed me!
Nice avatar, OzzyFauntleroy.*
* Yes, yes. I know it's the friggin Sun King, but leave me to my little perversities.
Oz, are you saying it never did that before?
No, I'm saying I never realised it before; it may well have been like this all along but I have only noticed it recently.
Recipe:-
(1) Drive your car until the fuel range is low, or better still, until the chime starts to "blong" at you with warning at the HUD regarding fuel.
(2) Park the car on a horizontal surface. Take note of the gap between the rear tyre and its wheel arch. It should/could be bigger than the front's.
(3) Fill up the car with petrol (or in the case of Lord Pomposity, the car tells him to "feed her with a smile").
(4) Repeat step (2). But the front & rear gaps will be more consistent and aesthetically more pleasing to the eye.
See if you notice any difference. It maybe a subtlety only an owner can spot.
BHR4CE1
08-01-2007, 09:34 PM
Oz, are you saying it never did that before?
No, I'm saying I never realised it before; it may well have been like this all along but I have only noticed it recently.
Recipe:-
(1) Drive your car until the fuel range is low, or better still, until the chime starts to "blong" at you with warning at the HUD regarding fuel.
(2) Park the car on a horizontal surface. Take note of the gap between the rear tyre and its wheel arch. It should/could be bigger than the front's.
(3) Fill up the car with petrol (or in the case of Lord Pomposity, the car tells him to "feed her with a smile").
(4) Repeat step (2). But the front & rear gaps will be more consistent and aesthetically more pleasing to the eye.
See if you notice any difference. It maybe a subtlety only an owner can spot.
Um... HELLO?????? :tongue:
Am I missing something here? :shake:
Doesn't it make TOTAL sense that the rear end of the car would sit a little LOWER with a full tank, versus an empty tank? Why not park your car on a level surface...with an empty gas tank, and fill up the trunk with lots of stuff. There, did it go lower? Sure did! SEE??? That's the SAME thing as putting Gas in the tank...adding weight to the rear of the car.
Want your car to look like it has been lowered with coil-overs, but without the expense??? Let ME sit in your trunk! LOL :greenlaff:
Um... HELLO?????? :tongue:
Am I missing something here? :shake:
Doesn't it make TOTAL sense that the rear end of the car would sit a little LOWER with a full tank, versus an empty tank? Why not park your car on a level surface...with an empty gas tank, and fill up the trunk with lots of stuff. There, did it go lower? Sure did! SEE??? That's the SAME thing as putting Gas in the tank...adding weight to the rear of the car.
Want your car to look like it has been lowered with coil-overs, but without the expense??? Let ME sit in your trunk! LOL :greenlaff:
I think you're right. Simple as that, which is the obvious reason I was thinking. But I was wondering if there were other mechanisms contributing to that. (No, not Lord Bear's weight. I meant BMW engineering ones).
BHR4CE1
08-01-2007, 09:56 PM
I think you're right. Simple as that, which is the obvious reason I was thinking. But I was wondering if there were other mechanisms contributing to that. (No, not Lord Bear's weight. I meant BMW engineering ones).
Most of the time, the most logical and obvious explanation is the right one.
AusBmw
08-02-2007, 02:38 AM
Hmm oz mate i would say it's quite normal,I mean i run around for a few days with sub 20L then the light comes on,fill her up till she wont take any more 75L's of 98 PULP and drive of,my lord,the thing feels like it's got a few tons of lead in it,and she drops a bit to,not a lot,the weight-density of gasoline is about 737.22 kg/m3.
Not sure if it has any thing to do with it,but when it's cold petrol is denser.