BMW may be changing their mind

why would they give up on diesel? don't they sell the expensive high end epa sanctioned design?

beemer buyers can afford and desire the most expensive tech, vs vdub drivers who consist mostly of unemployed college grads.

 

The engine on the i3 REX isn't intended to provide full operation to the car, but as just a range extender to the EV. The intention as intended was that the driver would be aware they would be exceeding the EV range long before they got to a near dead battery, and they would turn the ICE on to keep the battery charge up, perhaps as early as the pack at 80% SOC, while still enjoying full performance from the car.

CARB insisted on hobbling the software though. So US models can't turn the the ICE on until the pack is down to 15%. Which is why they have problems in climbing mountains and tall hills in hybrid mode. If a US model can't be turned back to European operating specs, I wouldn't even consider a used one.

As for their diesels, yes, BMW didn't cheat. The BMW used on the West Virginia Tech study exceeded NOx limits on one test circuit, but the researchers felt no need to look further into it by running the car through the EPA test cycles, as they did with the VWs. Others were likely measured exceeding limits by onboard test equipment in other studies too. Guess what, gasoline cars have been measured exceeding limits by such equipment too. Like the MPG results, the regularitory tests don't completely mirror how cars are actually driven.

 

A REX is an EV first, and is more of an EV than EREV.

The i3 is a small, light weight platform to maximize the range and efficiency of the BEV model. BMW wasn't intending it to be a full function car in terms of size and range, but they knew a sub 100 mile range would discourage sales. So they made the REX version to assuage the range anxiety of potential buyers.

Like BMWs, it is RWD, with the ICE and motor in the rear of the i3 REX. Part of the inefficiency it has in hybrid is because it is a pure series hybrid. If you want efficient and full performance in hybrid mode, you'll need a larger ICE with a transaxle that allows some parallel hybrid function. This will add weight, and take up some space in the cargo area. I don't think there is any space under the 'hood' for the power plant. Even if there was, the battery pack is a skateboard layout. Some of it can be removed to save weight, but the platform doesn't have a transmission tunnel. If BMW went FWD, that tunnel would still be needed in some form for the exhaust and emission equipment.

For those that want an PHEV, BMW has the 330e.

The REX concept of being mostly BEV with a range extender that provide ~75% of the car's power needs with the rest coming from the grid charge on longer than EV range trips is how I pictured the Volt working when first announced. I have a longer than typical commute, and the only time the i3 REX should need to use the ICE is during the very cold days of winter.

A more efficient ICE might be had for a future i3 REX, but I believe size and weight were bigger concerns than hybrid efficiency. It would be dead weight for more time than the ICE in the Volt. On the hybrid to EV efficiency scale, better to tip towards the EV side for its design. The i3 is the most EV efficient BEV to be had now.

 

bmw's problem, is that they are another high end builder, not willing to make a car for the masses. and that becomes our problem.

 

True in the US, but they have more reasonable offerings in Europe.
The 328d we get is just the 320d there, with corresponding lower price.

 

Which is how the i3 REX works, with some tweaks for creature comfort and sanity, "When the range-extender turns on, you cannot hear it at all from inside the car because it initially runs in the lowest of the three power levels. If you continue to drive at speeds higher than 40 miles per hour, it will kick up to the next power level and you can then hear a low hum from inside the car. If you are driving at highway speeds, it will jump up to its highest (28kW) power output, and then you can definitely hear it." - 8 Key Questions about the BMW i3 Electric Car | PluginCars.com

The three power levels is what Audi settled on with their A1 PHEV prototype fleet. The even smaller Wankel engine originally ran at one set speed for efficiency. The constant, steady hum that was disconnected from vehicle speed proved to be unsettling to most drivers and passengers, though.

At 75% SOC, it is possible to manually turn the range extender on with a model available outside the US. I would guess the ICE would shut down once the SOC hits some value above that. With the 3 power levels, the goal is probably more to keep the battery level around the SOC level it was at when the ICE was turned on than to recharge to battery. It can maintain 75mph cruising on flat roads for as long as it as gas. Go faster, climb steep slopes, or heavy acceleration that exceeds the ICE's output, and it draws from the pack.

Unless the SOC is 3% or less, the ICE shuts down at stops and speeds up to 15mph.

If not turned on manually, the range extender will kick on at 6% SOC. The US version doesn't have a manual control of the ICE, and it only turns on at this low charge point. Which hampers performance because there isn't more of a buffer in the battery when the car is on gasoline. Every PHEV out there now lets the driver decide when it is best to go into hybrid mode to save grid charge for when it will be best to use it. But PHEVs don't get the desirable CARB credits. So BMW agreed to so conditions to get some credits for the REX.

In the US, the REX fuel tank is a half gallon smaller than the European one at 1.9 gals., and there is the lack of the aforementioned manual start of the range extender. Which makes the i3 REX like the first year Volt, but with an ICE that can't meet 100% of the car's potential power needs.

So the ICE might run more often, and possibly at less efficient speeds, in the US, than if the driver at had more control over its operation.

The efficiency of the ICE could be improved in later gens. Weight and packaging is likely more important for this one. The i3 BEV's high efficiency and range had much to do with the car's light weight. It and the REX use the same size battery pack. The ICE, generator, and attending systems drop the EV range from 81 to 72 miles.

 

A federal version of the REX would have been nice, but the number, and populations in, CARB states makes it cheaper to just sell the CARB version now.

It likely isn't hard to gain access to the European operation. It wasn't that hard to get EV mode in my 2005 Prius.

 

Fixed it.

 

Wish I had the link, but still remember the main points. About twenty years ago, European governments encouraged the production of diesel cars. While the tailpipe emissions are more than gas ICEs, the fuel economy is 30% greater so overall CO2 is reduced. They were optimistic diesel emissions could be cleaned up. So diesel cars rose to 50% of the mix in Europe. Now it turns out it's not as green as believed.

I found the link The rise of diesel in Europe: the impact on health and pollution | Environment | The Guardian

 

i think grumpy concurs with you.

 

But NOx is just one of many pollutants produced by mobile sources. All other emissions besides NOx, e.g., VOC, CO, PM, PN, and most unregulated pollutants like benzene, are lower on average for diesel vehicles compared to gasoline vehicles. I really don't understand why these European officials are solely focused on NOX emissions.

Even then, BMW diesel vehicles are doing well with respect to NOx emissions in Europe. In recent testing, one BMW diesel model had "real-world" NOx emissions than were below the regulatory limit ( Green Car Congress: Initial results from French NOx emissions testing of 100 diesels show high discrepancies between official and on-the-road results ).

 

but it's more difficult to achieve in a moderately priced car.

 

One well-respected damage model (APEEP) actually assesses that NOx emissions are BENEFICIAL in two heavily populated counties in the U.S. (looks like Orange County, CA, and Cook County (Chicago), IL).



Nick Muller's Homepage (graphic on right side of developer's page)


As a disclaimer, NOx does cause damage to public health and the environment generally, and I'm certainly not promoting additional NOx emissions, but it is not one of the more damaging emissions according to that source (ammonia, for example, has a maximum damage cost of $302,000/ton).

Edit: Graphic loaded in preview, but not when I posted it. The graphic can still be viewed at the link above.

 

as the protector of public health, the epa should be looking at all the emissions, and studying the health threats. seems like the science was finalized before it was finalized.