SLegacy99

There you go. You have proved my point. A 4 MPG Difference. Not ZERO.

IS-SV

Yes, only 4 mpg highway.
And 12 mpg city difference, that's huge.

SLegacy99

Exactly. And the fact is that long road trips or commutes on highways such as the Beltway around D.C. can often be interupted traffic jams. Nevertheless, Lexus should direct inject the 350 and 450h and we shall see what happens.



...Anyway, my guess is that the 316d suffers from a weight problem. Perhaps a 116d would do better.

Threxx

I already explained what makes the majority of the 3 or 4 mpg difference... it's the tuning of the gasoline engine and the CVT transmission, not the battery or electric motor, especially when on relatively flat highways without any interruptions in traffic flow.

The fact that the mpg gain is so much better in the city (especially as a percentage, or when you convert to gallons per mile) than on the highway demonstrates what a difference the hybrid drivetrain makes when it's able to contribute, and what little difference it makes when there's no braking and little coasting involved.

City mileage goes up 67% with the hybrid model. Highway only goes up 12 to 17%.

The 1-series platform shaves something like 6-7% off the weight of the 3-series IIRC. It'd help with acceleration, but not a whole lot.

Also, diesel engine fuel mileage suffers less due to weight than gasoline engines... so the difference may be even less than we'd expect. Lastly weight almost makes no difference in highway fuel economy

LexFather

The new RX has the newer tech. I want to remind everyone its not no bare bones bargain basement car. They are mostly loaded and weigh 4400 lbs. Their mileage is incredible.

I see value in both a solid diesel and a solid hybrid. I see no sense in this 116d and the INsight. Both are missing the point to me.

SLegacy99

Well you are wrong. The fact is that during highway cruising electric motors are in use and the battery does not deplete.

IS-SV

Who knows, because the mileage difference is relatively small at highway speeds and the electric motors, tires, gearing, tranny, aierodynamics, etc. can all contribute to a difference of that magnitude.

I've driven the new RX350, it was boring but nice and roomy.

SLegacy99

But the fact remains that the electric motors are running at 10-12 Kw to propel the car along with the ICE at highway speeds. The power isn't just going nowhere, the electric motors aren't just spinning in neutral, thus there is a fuel economy gain. This is why a Li-ion battery is ideal. The electric motors could draw more power (perhaps 20 Kw, maybe even 30) from such a battery, without depleting it as it would with a Ni-Mh battery (i.e. Topgear: Prius vs. M3). Thus not only would the ICE be less stressed = greater fuel economy, but also the ICE could be smaller, again hopefully reducing fuel consumption.

IS-SV

Yes, the electric motors are contributing some portion of that less than impressive gain in highway mileage. I'm confident the technology involved will only get better in coming years.

Threxx

Energy is not free. It can't be created out of nowhere. So please explain where the RX is generating energy to charge its battery on the highway during a road trip. You already sort of tried twice but your explanations made zero sense from a technical perspective. If you can't explain it, then provide me with a link.

edit:
I found my own explanation in wiki in the article on hybrid synergy drive:
So as I suspected, you aren't getting any energy for free here... the hybrid system simply acts as a way to balance the power created by the internal combustion engine... at some points the ICE is producing more torque than necessasry to move the vehicle at the speed demanded by the driver, and at other points it's delivering less. In a normal non hybrid vehicle if the vehicle is producing more torque than necessary, you accelerate... less, and you slow down, or else you compensate with the gas pedal (or cruise control does it for you) and the throttle position has to change or engine RPM has to change by unlocking the torque converter and/or dropping a gear. Since ICEs tend to work most efficiently at a set throttle position and engine RPM, the hybrid synergy drive system uses this +/- compensation system to keep the engine from having to change its RPM or throttle position to maintain the requested speed.

So it does contribute to highway mileage by allowing the ICE's engine operating conditions to stay more ideal, however all energy that it uses has been created by the ICE while driving. In other words it's created from gasoline... no miracles happening there. So this combined with the CVT and engine tuning contribute to the small gain in highway fuel economy.

SLegacy99

No, I don't think I agree with all of that wiki explanation. Like I said earlier, the CVT enables the car to coast so well that the electric motors reverse while coasting and provide a charge to the battery. Toyota/Lexus gives you a screen to watch where the energy is derived from. Green arrows from the electric motors means than the electric motors are generating the energy. Go drive one and see for yourself.

IS-SV

Green arrows make for a nice enjoyable and colorful display on the dash.

SLegacy99

It sure is distracting. I usually keep the mileage screen up myself that logs 5 minute intervals.

IS-SV

Yep and who knows if it's even accurate, it's purposely vague I suspect.

DustinV

Have you ever driven a modern diesel? I owned a car here in Germany that was pretty close to what this BMW 316d is like: a new W204 Mercedes C200 CDI. I believe I had 122 diesel horsepower under the hood and an insane amount of torque coupled to a five speed automatic transmission.

The performance? Obviously, the car wasn't blisteringly quick but I found the performance to be very satisfactory. Ok, so 0-60 took about the time same as this 316d - but the midrange performance was very impressive. It didn't matter if I was on the autobahn or a normal road, the C200 CDI had enough grunt to quickly accelerate at midrange speeds for a safe and quick overtaking. Take it from me: the 316d isn't as slow as you'd like to believe.

Anyway, when you buy a BMW you pay for the badge and the Euro-Dollar relationship. BMW, like all European manufacturers, practices prestige pricing. Why? Because people are willing to pay for this car. If the 316d should make it to North America (highly unlikely), it will come better equipped and will be cheaper than its European 316d counterpart - as is usually the case.


You're missing the fact that somebody interested in such a vehicle doesn't care about performance. Europeans view the acceleration time of this car as adequate. The point of this car is fuel economy.

If you want a bit more performance and fuel economy there is always a 318d or 320d (and other 3er models) to choose from. It's a shame that only the wonderful 335d is offered in the US because given my experience with the C200 CDI from Mercedes, I am almost positive the equivalent BMW 318d or 320d will be a bit more agile and sporty.

These are indeed great cars. It's a shame that people here judge them based on 0-60 times...