No gas guzzler tax for the M-DCT cars???

[skierman64]

According to "Road and Track" April 2008, pg 23. "BMW says that not only will M-DKG give the M3 quicker acceleration, but it also "reduces fuel consumption by a signficicant margin""

I hope we soon know the definition of a significant margin. My theory is, we're only 10% away (22mpg) from a $700 savings in gas guzzler tax or 20% away (23mpg) from no gas guzzler tax at all. Here's to hoping the DCT cars incur no gas guzzler tax at all; 20% could be a significant margin.

The $2700 extra for the M-DCT seems more reasonable if I save $1300 on GG tax. I can use that $1300 elsewhere. Hell, that's 3 or 4 track weekends.

[the_stranger]

I dont think thats going to happen.

[nusevad]

Originally Posted by the_stranger

I dont think thats going to happen.

But we still dont know yet, so there is still hope!

[batchelorc]

Don't tease!

[skierman64]

Well I haven't spend the $1300 saved yet, but there sure is room in my bank account for it to stay there.

Any higher mileage rating will reduce the GG tax.

[M2MG17]

There most likely will not be any diff. The savings are there but are not significant enought to reduce this

[sayemthree]

dude ! wake up!! you are dreaming again!

[WCH]

The GGT was on my order sheet for my M-DCT coupe. Would be nice but doesn't look like it will happen.

[swamp2]

We already quite a bit of info and info on M-DCT and we can at least bracket the likely difference between 6MT and M-DCT.

M3 Coupe:
MT (EU): 17.9/9.2/12.4 (l/100km urban/extra-urban/composite)
M-DCT (EU): 17/9/11.9

So

M-DCT gains: 5%/2%/4%

MT (US): 14/20 (mpg city/highway)

Estimates M-DCT US EPA mpg rating: 14.7/20.4 (big assumption which is probably not very accurate: % gains on EU and US test cycles are the same). Also if the least aggressive AT modes give the best mpg can the best AT mode be chosen for the test?

CAFE std is used to figure GGT and is approximately: combined mpg = (1/(0.495/city + 0.351/HW)) + 0.15

M3 MT "combined" = 19.1, GGT = $1700.

But we know this is not quite right, the M3 MT GGT is in actuality only $1300.

Using the 14.7/20.4 figures (not sure if they have to be rounded or not, anyone?) we have M-DCT "combined" = 19.8 mpg. Perhaps we will see as good as 15/21 (or with lucky rounding) which yields a "combined" = 20.3.

So the best/worst case calculated combined gains are 1.2/.7. Lets use those gains to do some bracketing (see table below)

20.5 +.7 = 21.2 -> No change
20.5 + 1.2 = 21.7 -> $1000
21.4 + .7 = 22.1 -> $1000
21.4 + 1.2 = 22.6 -> No tax

I guess I'll place my bet that the GGT goes down to $1000. I suspect GregW might have some comments/suggestions/corrections on this work. Greg?



For reference the tax schedule is as follows:

Combined fuel economy of: Amount
at least 22.5 mpg No tax
at least 21.5, but less than 22.5 mpg $1000
at least 20.5, but less than 21.5 mpg $1300
at least 19.5, but less than 20.5 mpg $1700
at least 18.5, but less than 19.5 mpg $2100
at least 17.5, but less than 18.5 mpg $2600
at least 16.5, but less than 17.5 mpg $3000
at least 15.5, but less than 16.5 mpg $3700
at least 14.5, but less than 15.5 mpg $4500
at least 13.5, but less than 14.5 mpg $5400
at least 12.5, but less than 13.5 mpg $6400
less than 12.5 mpg $7700

[skierman64]

The $1300 GGT was on my order sheet as well. Perhaps they just haven't accomplished the EPA test of a DCT car so they put it on there because they didn't know the EPA mileage number yet.

Why would BMW say a significant improvement if the difference isn't significant. +10% is what I'm hoping for. $300 less in taxes is good with me.

[Deathboy]

Thats weird if its true?

[nusevad]

Originally Posted by skierman64

The $1300 GGT was on my order sheet as well. Perhaps they just haven't accomplished the EPA test of a DCT car so they put it on there because they didn't know the EPA mileage number yet.

Why would BMW say a significant improvement if the difference isn't significant. +10% is what I'm hoping for. $300 less in taxes is good with me.

yea 300 less is nice.

I still havnt got my order sheet yet...

[darkalley]

I remeber being in a dodge viper that shifted from 1 to 3 under low rpms to improve mpg. Should be interesting to see.

[JEllis]

Originally Posted by chasem3

There most likely will not be any diff. The savings are there but are not significant enought to reduce this

It all depends on the design of that 7th gear...

Keep in mind that the Vette would have a GG tax if it werent for the economy of its 6th gear..

Jason

[rvacha]

While M-DCT *could* be more efficient, it has a manual mode and like all manual trannies can be driven extremely bad. I'm guessing there will be little difference in GGT unless the mentality of the EPA has changed lately

[Hotan Braskey]

Originally Posted by JEllis

It all depends on the design of that 7th gear...

Keep in mind that the Vette would have a GG tax if it werent for the economy of its 6th gear..

Jason

The Vette does have a really tall 6th gear, but I think the only reason it makes these great fuel economy figures is because it has the 1st to 4th gear skip engineered into the transmission unless you are driving hard.

[swamp2]

Originally Posted by JEllis

It all depends on the design of that 7th gear...

Keep in mind that the Vette would have a GG tax if it werent for the economy of its 6th gear..

Jason

We know the M-DCT 7th gear ration and FD (not the same as the MT). It is basically a fuel economy oriented gear ratio.

Originally Posted by rvacha

While M-DCT *could* be more efficient, it has a manual mode and like all manual trannies can be driven extremely bad. I'm guessing there will be little difference in GGT unless the mentality of the EPA has changed lately

The EU data shows not that is could but that it does. The US tests will be different but I'd be willing to bet they will still show an improvement.

[JEllis]

Originally Posted by Hotan Braskey

The Vette does have a really tall 6th gear, but I think the only reason it makes these great fuel economy figures is because it has the 1st to 4th gear skip engineered into the transmission unless you are driving hard.

Not sure if you are talking about the auto tranny but I was referring to the 6MT Vettes....

The vettes fuel economy sucks in any other gear besides 6th. On the highway the vette can easily get over 30mpg at 80 mph. Whats even more amazing is at this speed the engine is humming along at just over 2K rpm. My dad used to brag about the 40mpg he got on road trips in his C5.

If the 7th gear in DCT is anywhere near the same (I guess it is a fuel economy oriented gear) then the overall fuel economy will be greatly improved...

Jason

[enigma]

Originally Posted by JEllis

If the 7th gear in DCT is anywhere near the same (I guess it is a fuel economy oriented gear) then the overall fuel economy will be greatly improved...

Its not. Its a tiny bit taller than the 6mt but not enough to make a dramatic difference. The DCT will get most of its improvements from avoiding lift on shift and the ability to keep the RPMs in a tighter range.

[sayemthree]

The EPA formula determines what BMW will pay the FEDs, not what the consumer pays. BMW could charge no GGT to the consumer , but they would have to pay the feds.

[SpencerM3]

Interesting take. I would imagine that the GGT will still apply.

[devo]

Originally Posted by SpencerM3

Interesting take. I would imagine that the GGT will still apply.

He is right. If BMW elected to pay the fees there would be no GGT to the consumer. In fact, I believe that they pay part of those taxes on some cars.