MPG and the M3

[ersin]

Originally Posted by ArtPE

I disagree with the statement if you care about fuel costs you shouldn't buy this car...in fact just the opposite, if you DON'T care about fuel costs you shouldn't buy this car...you're careless with money, probably don't have any, and never will

Let me restate. If you have problems with fuel costs you shouldn't buy this cars. Does that make better sense?

[enigma]

Originally Posted by cosmos515

I would bet you guys dont see 15mpg with the M3. I would say in the real world..closer to 11.

Since owning my E46 M3 I have averaged ~19.7mpg combined over the last 6 years. Its amazing how drivign style impacts economy, the more you are using the brakes, the worse the economy.

I did have a few weekends of sub 6mpg mixed in there. At Laguna Seca its about 1/2 gal per lap.

[jaiman]

Originally Posted by ArtPE

people who accumulate wealth watch long term expenditures...
if you save $200/month over 20 years at 3% that's 68k with the interest...a good portion of the cost of a car...

if you plan to save for 20 years, and take a 3% return, you're a financial moron!

[cameba5]

ive been doing pretty well, i have about 440 miles and only three fill ups, but i try to shift early, and watch my right food (most of the times.... :-))

[T Bone]

Originally Posted by Samifumi

Again, the magical mystical M-DCT might pay for itself should it improve fuel economy as suggested. I've read it should improve consumption by up to 3 mpg.

Anyone thinks they are going to get 3 mpg with DCT over 6MT is smoking crack. If this were even remotely true, BMW would never produce the 6MT. Try more like 0.5 MPG, if anything at all.

Originally Posted by 1960apache

I hate to join this "Banter the M3" post, but I was thinking about that alot lately. How does a 4 litre engine get such horrible gas milage? The corvette gets 20-28 with 400-500hp, I have a Dodge diesel that gets 17mpg hauling 13,000 lbs. I love the new M3, but my rational side is kicking in, 70K, plus gas guzzler, + tax, tags, washing, horrible gas milage etc.!!! This is ruining my fantasy! After all it is just a car I tell myself, and the worst possible item to put money into. I actually just found an 06 325Ci, loaded, black on black, 5k on the odometer, it is a young hotshot that works with my broker, who need to dump it fast for the cash 22-25k!!!! I think it is maybe 2/3 the car the M3 is, but probably 1/3 the price though! Actually, as long as I am driving an immaculate black manual transmission 3 series, I am happy!!! Oh the misery!!!

There are a couple of considerations...

The Z06 6th gear is extremely tall and is used for cruising mainly. The BMW uses 6 well spaced gears.

More importantly is the design of the engine. The Chevy LS7 achieves excellent volumetric efficiency (ability for an engine to breathe / generate torque measured as a ratio against the theoretical maximum for a given displacement of a cylinder) in lower RPMs. This means the LS7 gives good torque low in the RPM band and coupled with a tall 6th crusing gear, it has enough torque while sipping fuel in low rpms to push the car to cruise at highway speeds.

The S65 / S85 BMW engines achieves maximum volumetric efficiency very high in the rpm band, which means it doesn't make power until higher in the rpm band. This is great for acceleration when coupled with a close ratio gearbox.

Fuel economy was determined by BMW's preference for high revs ala F1 style. Nature of the beast.

Originally Posted by swamp2

Wow, impressive. Great for you!

On the DCT mpg thing. Read up boys (on this forum), +3 mpg = no way in hell. It is going to be more like 1-2.

My fuel bill for the M6 and 335xi last year was ~$6000.

• My M6 had 13.4 mpg (17.6 l / 100 km) over the past 15,000 kms. Sucks gas like crazy.
• My 335xi has an average of 11.0 l /100 km (21.4 mpg) over the past 5000 km.
• My E46 M3 had an average of 12.2 l / 100 km (19.3 mpg) for the 50,000km that I had it.
• My E36 M3 had an average of 10.8 l / 100 km (21.8 mpg) for the 60,000 km that I had it.

I predict the E92 M3 will give most people 16 mpg. The best bang for the gas buck car that I have had is the 335xi......

[ArtPE]

Originally Posted by jaiman

if you plan to save for 20 years, and take a 3% return, you're a financial moron!

it is a conservative estimate, and looking at the market now, may not be far off...
3% per annum compounded continuously...actual return over 20 is 82%
btw, what's a 1 yr t-bill doing?

someone who would reply to a post as you did is a moron PERIOD.

[jaiman]

Originally Posted by ArtPE

it is a conservative estimate, and looking at the market now, may not be far off...
3% per annum compounded continuously...actual return over 20 is 82%
btw, what's a 1 yr t-bill doing?

someone who would reply to a post as you did is a moron PERIOD.

Do you actually think the market will return 3% per year over the next 20 years??

I wasn't insulting you, but since you insisted on insulting me, aren't you the guy whose in his 50's and hasn't cracked 200k in annual earning? Perhaps people should take financial advice from someone who knows that 3% annually will barely keep you above historical inflation. Jackass.

[Samifumi]

Originally Posted by T Bone

Anyone thinks they are going to get 3 mpg with DCT over 6MT is smoking crack. If this were even remotely true, BMW would never produce the 6MT. Try more like 0.5 MPG, if anything at all.

I'll rush to my own defense and remind the board that I believed 3 mpg is optimistic, and that driving style will have more impact on fuel efficiency than a slick new transmission. But the slick new transmission will help.


I've read a Reuters news release that said DCT could improve efficiency 10-15 percent (let me find it and I'll post it). And like I said before, I'm giving the DCT the benefit of the doubt until I see it in action.

[T Bone]

Originally Posted by Samifumi

I'll rush to my own defense and remind the board that I believed 3 mpg is optimistic, and that driving style will have more impact on fuel efficiency than a slick new transmission. But the slick new transmission will help.


I've read a Reuters news release that said DCT could improve efficiency 10-15 percent (let me find it and I'll post it). And like I said before, I'm giving the DCT the benefit of the doubt until I see it in action.

BMW also had a press release that somehow the new M3 was more efficient than the old M3 (see my bet with MKOESEL).

The ONLY way the DCT would get signficantly better fuel economy would be a result of the taller gearing that a 7 speed would give....improved fuel economy would have absolutely nothing to do with the gear switching mechanism.

[ArtPE]

Originally Posted by jaiman

Do you actually think the market will return 3% per year over the next 20 years??

I wasn't insulting you, but since you insisted on insulting me, aren't you the guy whose in his 50's and hasn't cracked 200k in annual earning? Perhaps people should take financial advice from someone who knows that 3% annually will barely keep you above historical inflation. Jackass.

this coming from someone who's IQ is less than my ht in inches...

btw: I'll make more than you ever will...in real money, not your e-money or canadian paper

cockbreath

[jaiman]

Originally Posted by ArtPE

this coming from who's IQ is less than my ht in inches...

btw: I'll make more than you ever will...in real money, not your e-money or canadian paper

dikwad

wow, I'm shocked, you're over 12 feet tall. That's awesome.


I'm not going to bother with you anymore, I pointed out a small error, in a joking way, and you called me a moron. But whatever hillbilly, have a nice life trying to retire on GIC returns.

[ArtPE]

Originally Posted by jaiman

wow, I'm shocked, you're over 12 feet tall. That's awesome.

I'm not going to bother with you anymore, I pointed out a small error, in a joking way, and you called me a moron. But whatever hillbilly, have a nice life trying to retire on GIC returns.

you may have convinced your girl friend that this is 10"

>-------------------<

but you know better...

that's all cheesedik, enjoy your slow ride into mediocrity

[jaiman]

Originally Posted by T Bone

BMW also had a press release that somehow the new M3 was more efficient than the old M3 (see my bet with MKOESEL).

iirc BMW said the new enginge was 7% more efficient, but I've never seen anything that said what that was in reference too.

[Samifumi]

Originally Posted by T Bone

BMW also had a press release that somehow the new M3 was more efficient than the old M3 (see my bet with MKOESEL).

The ONLY way the DCT would get signficantly better fuel economy would be a result of the taller gearing that a 7 speed would give....improved fuel economy would have absolutely nothing to do with the gear switching mechanism.

http://www.reuters.com/article/press...08+PRN20080113

Likely not the same company that produces the DCT used in the M3, but still an assertion that a DCT will improve efficiency up to 15% (over conventional automatic transmissions).

[ArtPE]

http://www.getrag.de/en/252

I think this is the M3 DCT

re: efficiency, I think BMW means 7% more HP for the same fuel, which does not translate directly into MPG...weight, wider tires, etc.

[T Bone]

Originally Posted by jaiman

iirc BMW said the new enginge was 7% more efficient, but I've never seen anything that said what that was in reference too.

Exactly, this is marketing BS that means nothing except you get worse fuel economy.

Originally Posted by Samifumi

http://www.reuters.com/article/press...08+PRN20080113

Likely not the same company that produces the DCT used in the M3, but still an assertion that a DCT will improve efficiency up to 15% (over conventional automatic transmissions).

Is this what you mean "Transmission efficiency can be increased with a LuK dual clutch in dual clutch transmissions (DCT), resulting in 10 to 15 percent less fuel consumption in comparison to conventional automatic transmissions.
Hybridization of the twin clutch transmission leads to another 10 percent
savings in fuel economy. "??

Again, this is BS. If the MDCT gives an improvement in fuel economy, it will be from gearing. Feel free to believe what you want only real world numbers matter. I have fortunately accumlated real world numbers for the last 3 generations of M cars (except the E39 M5 and the E92 M3).

[godot]

Originally Posted by T Bone

There are a couple of considerations...

The Z06 6th gear is extremely tall and is used for cruising mainly. The BMW uses 6 well spaced gears.

More importantly is the design of the engine.

There's another big factor that I didn't see anyone mention: The Corvette's manual tranny has a magnetic gate that forces you to skip from 1st to 4th gear, except when accelerating hard. So in casual driving, you physically cannot enter 2nd or 3rd. (Of course, a lot of people find this massively obnoxious and disable it with an aftermarket wiring harness.) Presumably, the software for the automatic tranny does something similar.

As to highway mileage, coeff of drag is <0.29 in the Vette vs. 0.32 in the M3. Part of the tradeoff of having more passenger and cargo room, I suppose.

[Samifumi]

Originally Posted by T Bone

Feel free to believe what you want only real world numbers matter. I have fortunately accumlated real world numbers for the last 3 generations of M cars (except the E39 M5 and the E92 M3).

Congratulations. As you said, only real world numbers matter. Different individuals, different driving styles, different numbers. Thank you for affording me the opportunity to make my own assessment.

[enigma]

Originally Posted by godot

There's another big factor that I didn't see anyone mention: The Corvette's manual tranny has a magnetic gate that forces you to skip from 1st to 4th gear, except when accelerating hard. So in casual driving, you physically cannot enter 2nd or 3rd. (Of course, a lot of people find this massively obnoxious and disable it with an aftermarket wiring harness.)

There was speculation BMW was using the numbers for auto mode with DCT where the RPMs can be kept out of the "silly" range for normal driving.

[ersin]

Originally Posted by godot

As to highway mileage, coeff of drag is <0.29 in the Vette vs. 0.32 in the M3. Part of the tradeoff of having more passenger and cargo room, I suppose.

Cd, i.e. drag coefficient, is only one parameter. The other significant factor is reference area. It's not exactly frontal area, but you can use this number. All other things being equal, viz. air density, multiply the Cd and A together. The car with the lowest number has the lower drag.

The vette not only has a lower Cd, but it also looks like it has lower area. So, much less drag for a vette than an M3.

[rvacha]

According to Bimmer Mag May 2008 the M-DCT improves economy 0.8MPG in the EU composite test

And making a net 3% over inflation for the next 20 years might make you a hero, not a moron

[JEllis]

wow this discussion is getting in the weeds.....

Jason