why does e70 get better mpgs than e53
 

can your x5 experts explain to me,

why the new e70 gets nearly 18-20 mpgs, which is a huge improvement over the e53 which usually got around 15-16 mpg...

can anyone shed what is so different between the two models to warrant the better gas mileage figures?

From BMW docs:

Performance & efficiency
• New engines in both models:
---3.0si – N52 6-cylinder engine with Valvetronic, magnesium/aluminum composite construction and other new features; 260 hp/225 lb-ft. torque
---4.8i – N62 V-8 engine, displacement increased from 4.4 to 4.8 liters; retains Valvetronic and aluminum construction; 350 hp/350 lb-ft. torque
---6-speed automatic transmission now standard in both models (previous 3.0i: 5-speed automatic optional, 6-speed manual standard)
---Automatic transmission includes extensive improvements for higher efficiency, quicker response and shifting, and finer adaptation to driving style and conditions
---New-type electronic transmission selector, similar in concept to that of 7 Series but on console instead of steering column
---xDrive fulltime all-wheel drive system, electronically controlled with variable front/rear torque split & traction control

-New technologies enhance fuel efficiency:
• Valvetronic variable valve lift (new to 6-cylinder X5 model)
• Rolling-resistance-optimized tires
• Delivery-regulated fuel pump
• On-demand power steering via electrically controlled bypass valve
• Pentosin power-steering fluid; revised viscosity index reduces power requirement at low fluid temperature
• Improved control of climate-control compressor’s clutch
• New-type rear differential

Forward progress.

In the case of the 3.0si, the E70's N52 engine has newer valve management system (valvetronic), double-VANOS, lower weight-per-hp ratio (lightest 6-cyl in the world).

70 4.8 vs 53 4.4
 

I don't have figures to back this up but having many miles on the 53 and just 18000 on the 70 my seat of the pants says the 53 may be better. They are both about the same on the highway and my 70 is worse around town. Can't say that for all the X's but for my cars thats the way it shakes out!

I don't think that they do get better mileage. The E70 has some more technology, but is heavier. Driving style makes more difference than anything else.

The US government fuel consumption test was changed, so the published numbers are different. You can't compare published figures for different years of vehicles any longer, unless you read a chart that has the different tests listed side by side. In theory, published figures should be worse for 2008, but there are so many adjustment factors included in the published number that it is a bit of a joke.

On long trips I actually did a little better with the E53.

Must be the valvetronic engine. I have an E53 4.8is and get similar gas mileage.

My 2006 E53 did about 18-19MPG. Now I am doing 16-17MPG with the new 2008 E70. I wanted to ask that question for about 4 months.... Why is that?

I thought I was getting better mileage on my '04 E53 than my E70. The added 3rd row makes the car heavier, burn more gas.

My 4.8 with 3rd seat gets close to 14 mpg. Not very green. Not sure what the rest of your 4.8 folks are getting...

my e70 3.0si gets 18mpg now.

My '01 3.0 that I put 88K miles on used to get 15.4mpg in normal mixed driving. my '09 with only 3400 miles just got 16.5 mpg on last tank but has been averging 16.2 to 16.4.
I do use the manual shift much more than the old one because it shifts much more quickly and cleanly than the older version.

Highway mileage seems exactly the same in the mid 21 and low 22 mpg.

Many reasons.

Throttle calibration
Valvetronic
6-speed automatic
Gearing- it's taller.
slightly better aerodynamics (0,34Cd versus 0,35Cd I believe)
Reduced rolling resistance in tire choices.

International models:
Active aerodynamics
Brake Regeneration

Remember though: It's not what you drive, but how you drive. I have a long-term average of 8,9l/100km in my X3 despite many cold starts and short trips in a mountainous region.

My 07 4.8i just got 13.5 MPG on local stop and go type driving. The best I've done on the hwy is 19.4. That was 100% hwy except for pit stops.

after 3900kms computer shows 20.6mpg with 90% hwy. mostly 2 hr trips to a near by ski resort.

When BMW announced the E70 the official line was that the new V8 used 5% less fuel than the outgoing E53 model while the new 3.0-litre used 14% less and the diesel 7% less. All using the same EEC test method.

Reasons why: New engines, new transmissions, improved aerodynamics, etc.

In reality IMO there's nothing in with the V8 and the diesel, perhaps a tad with the petrol six. As JCL mentioned, it's all about driving style (and driving environment).

BTW: My 3.0d gets 27mpg (US) and I don't spare the horses...

I believe the e70 4.8 is exactly the same as the 06 and earlier e53 4.8.

my 07 4.8 gets ~14.5mpg. close to ~20k miles on the odo.

what about the 3.0\?

I too think the E70 gets better mileage then E53, nothing incredible, I have noticed though that with the extra gear in the new 6speed auto revs stay much lower, unless in DS, I'm sure this is a big part of it


....fraser I like your avatar photo

Mr. Black,

Your avatar has a certain charm to it as well...