Originally Posted by Centurion' date='Oct 8 2005, 12:21 AM

[quote name='EBMCS03' date='Oct 7 2005, 10:06 PM']HAHAHAHA LOOK what you made me do!


Guess What I did today?





I took out the spare and jack out of my trunk.?

Originally Posted by donv' date='Oct 8 2005, 07:46 AM

I have the BMW mobility kit. I'm going to post "Trunk Funk" pics today. Let's hear it for the E60 weight reduction program.

Originally Posted by Centurion' date='Oct 8 2005, 10:02 PM

[quote name='donv' date='Oct 8 2005, 07:46 AM']I have the BMW mobility kit. I'm going to post "Trunk Funk" pics today. Let's hear it for the E60 weight reduction program.

Originally Posted by Centurion' date='Oct 8 2005, 10:02 PM

[quote name='donv' date='Oct 8 2005, 07:46 AM']I have the BMW mobility kit. I'm going to post "Trunk Funk" pics today. Let's hear it for the E60 weight reduction program.

Originally Posted by Stealthblue' date='Oct 8 2005, 10:37 PM

[quote name='Centurion' date='Oct 8 2005, 10:02 PM'][quote name='donv' date='Oct 8 2005, 07:46 AM']I have the BMW mobility kit. I'm going to post "Trunk Funk" pics today. Let's hear it for the E60 weight reduction program.

Originally Posted by donv' date='Oct 8 2005, 11:47 PM

No Atkins would not allow carbs. We need carbs or the equivalent--whatever BMW's fuel injection system is called. I couldn't think of a more clever reply. I am streeeaaatching.

Originally Posted by donv' date='Sep 18 2005, 07:18 PM

Hi All (I just noticed after all this time--Esthetic = Aesthetic ~0{:^)):

First, here is a question. How many miles would an average driver get on the 545i?s Dunlop run flats? The answer affects the economics of my/our individual weight-savings thoughts. You?ll have to factor in your particular circumstances. Also, note that I am not working with package pricing below--just with per wheel/tire prices. Forgive me for any mistakes; please let me know if you see any or question anything in the calculations. I?ll adjust or clarify.

1. By buying, for example, Michelin Pilot Sport PS2's, one can save the following (all weights below in lbs.) over the Dunlop run flats.

2(32 - 25) + 2(29 - 24) = 24 lbs. Given that unsprung weight is being saved, the sprung-weight equivalent is about 2(24) = 48 lbs.

2. By buying, for example, BBS RGR's, one can save the following over the stock sports package wheels.

2(34(?) - 21.2) + 2(32(?) - 19.4) = (approx.) 51 lbs. Given again that unsprung weight is being saved, the sprung-weight equivalent is about 1.5(51) = (approx.) 77 lbs.

3. The donut tire and jack weight about 37 lbs., together, while an after-market exhaust is likely to be about 30 lbs. lighter than the stock behemoth.

So, in sprung-weight terms, one can save about 48 + 77 + 37 + 30 = 192 lbs. with ease and without hurting the esthetics any if at all.

4. Given use of the lbs./Flywheel HP ratio, 192 pounds translates into about 192 / 10 = about 19 flywheel HP--or (48 + 77) / 10 = 125 / 10 = about 13 flywheel HP from the wheels/tires alone.

So, the first question is how about the economics of obtaining, for example, the portion of the increase in flywheel ?HP? attributable to the wheels/tires alone? Suppose that one will need to replace his or her run flats before disposing of the 545i. If so, then the cost of the extra tires is pretty much nil and is ignored below for ease. And, given a US$ price of 2($702) + 2($731) = $2,866 for the RGR?s and that one could sell the wheels, plus what's left of the Michelins, when disposing of the 545i for half the cost of the wheels ($1,433), then the cost of the wheels is $1,433.

5. So, the extra 13 "HP" from the wheels/tires alone cost about $1,433 / 13 = about $110.23 per HP--which is somewhat economical given, for example, that a Dinan trottle body, when installed by a Dinan certified shop, will cost, with a 10% discount on the part, about $685--which yields a cost per flywheel HP of about $685 / (8 / .85) = $685 / 9.4 = about $72.78. And, the wheel/tire package also will result in more that just an increase in HP?specifically, it will improve handling and some might say the esthetics. Finally, the run flats and factory wheels would be available for use?say on trips. I am assuming that the throttle body will not be sold when the 545i is disposed of.

6. Similarly, consider the cost, for example, of a B&B exhaust. The cost if installed by a BMW dealer, after a 10% discount on the part, is about $1,063. The related flywheel HP gain is about (10 RWHP / .85) + (30 lb. weight savings / 10) = about 15 HP. The cost per HP is ($1,063 / 2 / 15 = about $35.44 assuming the exhaust can be sold net eventually for half of its cost (about $532).

7. Together, all the costly weight savings, plus actual HP gains from the related items, gives a net cost of ($1,433 + $685 + $532) = $2,650. The cost per HP is $2,650 / (13 + 9.4 +15) = $2,650 / 37.4 = $71?which is similar to the per HP cost of the throttle body, itself.

8. So, the 545i ends up with 325 + 37.4 = about 362.5 flywheel ?HP.? If one throws in the 37 / 10 lb. saving from removing the spare tire, then the 545i?s flywheel HP is about 366?which is not too shabby. Thus, either way, one ends up with performance in the 550i range and is much better off not buying a comparable 550i if he or she already owns a 545i (i.e., consider loss on 545i and probably non-discounted or higher discounted price of 550i, price increase on 550i, etc., etc., and etc.) (ignoring the other new features of the 550i--which mean nothing to me).

The final cost per flywheel HP is $2,650 / (37.4 + 3.7) = $2,650 / about 41 = about $65?but no spare in the car.

Phew. I?m tired; I?ll keep checking my calculations?later. Any thoughts?

Originally Posted by donv' date='Oct 14 2005, 03:24 PM

[quote name='donv' date='Sep 18 2005, 07:18 PM']Hi All (I just noticed after all this time--Esthetic = Aesthetic ~0{:^)):

First, here is a question. How many miles would an average driver get on the 545i?s Dunlop run flats? The answer affects the economics of my/our individual weight-savings thoughts. You?ll have to factor in your particular circumstances. Also, note that I am not working with package pricing below--just with per wheel/tire prices. Forgive me for any mistakes; please let me know if you see any or question anything in the calculations. I?ll adjust or clarify.

1. By buying, for example, Michelin Pilot Sport PS2's, one can save the following (all weights below in lbs.) over the Dunlop run flats.

2(32 - 25) + 2(29 - 24) = 24 lbs. Given that unsprung weight is being saved, the sprung-weight equivalent is about 2(24) = 48 lbs.

2. By buying, for example, BBS RGR's, one can save the following over the stock sports package wheels.

2(34(?) - 21.2) + 2(32(?) - 19.4) = (approx.) 51 lbs. Given again that unsprung weight is being saved, the sprung-weight equivalent is about 1.5(51) = (approx.) 77 lbs.

3. The donut tire and jack weight about 37 lbs., together, while an after-market exhaust is likely to be about 30 lbs. lighter than the stock behemoth.

So, in sprung-weight terms, one can save about 48 + 77 + 37 + 30 = 192 lbs. with ease and without hurting the esthetics any if at all.

4. Given use of the lbs./Flywheel HP ratio, 192 pounds translates into about 192 / 10 = about 19 flywheel HP--or (48 + 77) / 10 = 125 / 10 = about 13 flywheel HP from the wheels/tires alone.

So, the first question is how about the economics of obtaining, for example, the portion of the increase in flywheel ?HP? attributable to the wheels/tires alone? Suppose that one will need to replace his or her run flats before disposing of the 545i. If so, then the cost of the extra tires is pretty much nil and is ignored below for ease. And, given a US$ price of 2($702) + 2($731) = $2,866 for the RGR?s and that one could sell the wheels, plus what's left of the Michelins, when disposing of the 545i for half the cost of the wheels ($1,433), then the cost of the wheels is $1,433.

5. So, the extra 13 "HP" from the wheels/tires alone cost about $1,433 / 13 = about $110.23 per HP--which is somewhat economical given, for example, that a Dinan trottle body, when installed by a Dinan certified shop, will cost, with a 10% discount on the part, about $685--which yields a cost per flywheel HP of about $685 / (8 / .85) = $685 / 9.4 = about $72.78. And, the wheel/tire package also will result in more that just an increase in HP?specifically, it will improve handling and some might say the esthetics. Finally, the run flats and factory wheels would be available for use?say on trips. I am assuming that the throttle body will not be sold when the 545i is disposed of.

6. Similarly, consider the cost, for example, of a B&B exhaust. The cost if installed by a BMW dealer, after a 10% discount on the part, is about $1,063. The related flywheel HP gain is about (10 RWHP / .85) + (30 lb. weight savings / 10) = about 15 HP. The cost per HP is ($1,063 / 2 / 15 = about $35.44 assuming the exhaust can be sold net eventually for half of its cost (about $532).

7. Together, all the costly weight savings, plus actual HP gains from the related items, gives a net cost of ($1,433 + $685 + $532) = $2,650. The cost per HP is $2,650 / (13 + 9.4 +15) = $2,650 / 37.4 = $71?which is similar to the per HP cost of the throttle body, itself.

8. So, the 545i ends up with 325 + 37.4 = about 362.5 flywheel ?HP.? If one throws in the 37 / 10 lb. saving from removing the spare tire, then the 545i?s flywheel HP is about 366?which is not too shabby. Thus, either way, one ends up with performance in the 550i range and is much better off not buying a comparable 550i if he or she already owns a 545i (i.e., consider loss on 545i and probably non-discounted or higher discounted price of 550i, price increase on 550i, etc., etc., and etc.) (ignoring the other new features of the 550i--which mean nothing to me).

The final cost per flywheel HP is $2,650 / (37.4 + 3.7) = $2,650 / about 41 = about $65?but no spare in the car.

Phew. I?m tired; I?ll keep checking my calculations?later. Any thoughts?