Driving in B mode

[TonyWilliams]

1 )Toyota does not recommend towing....

My guess, and this is just a guess, is that if the car shuts down due to low charge, it puts the circutry in either a high regen mode or even automatically engages PARK. If that happens, towing would be a bad idea.

That doesn't happen; it's actually the opposite. When the charge state gets so low that the main contactors open, the car goes to NEUTRAL, not Park.

The reason they don't recommend towing is simple; it was neither designed nor tested for the additional weight of a towed trailer. The cooling systems, suspension, braking, etc are all based on the gross vehicle weight, and they didn't include trailer weight in this design. Why would they? For an extremely limited market vehicle with limited range and a short development period, built for one purpose (CARB ZEV credits), it would be nutty to waste time and money on this type of testing.

That doesn't mean it can't tow, as I do regularly. Clearly, if I overheated the inverter climbing a hill with 10,000 pounds, Toyota likely wouldn't cover that by warranty. The practical issue is that electric drive trains generate very little heat compared to a gas or diesel, therefore my concerns are small with pulling the 3500 pounds that the same chassis is approved for with a gas engine.

Braking is always a huge concern with towing, and again, as long as I have regen I will be mostly comfortable down a long hill. I would not be comfortable with just brakes on the Rav4 with no regen down certain hills with 3500 pounds behind me however. Naturally, it's wise to have trailer brakes.

The suspension has certainly been robust enough, and there's plenty of power.

 

[SeattleRav4]

Tow-er vs Tow-ee.
I was talking about towing a Rav4 not towing with a Rav4.
I agree that towing with a Rav4 should be no problem, accounting of course for the reduced range that a towed package would yield.
I also agree that towing a Rav4 should be no problem but the Toyota manual specifically RECOMMENDS against both.
I think I will go put mine in N tonight and push it just to see what happens. My guess is it will simply roll.

I guess if you towed it for a long distance, it is somehone possible for the motor to heat up since it would not be cooled. Though even that seems like a long stretch.

 

[TonyWilliams]

Tow-er vs Tow-ee.
I was talking about towing a Rav4 not towing with a Rav4.

Well, I might agree with Toyota to some degree here (to being towed). But, there is nothing to physically hurt, since it will be spinning the motor just like driving down the highway. Everything is lubricated.

You're just putting miles and wear and tear on the drive train that is not reflected by the odometer (hence a potential warranty cost issue for Toyota).

I would first prefer to use a tow dolly or disconnect the half shafts.

 

[adjackson3]

I just got my RAV4 EV last week and am still exploring it. My other EV is a 1999 Solectria Force.

Regarding use of regen. The Solectria has a rather aggressive regen and I like it. I use it all the time . All of my driving is around town and I frequently stop using just regen. In the seven years I have had the car, I have not had to do anything about replace the brakes. Regen saves lots of wear and tear.

I really like to watch the PWR & CHRG lights on the left of the instrument panel. I try and keep the green PWR light bar with as few bars as possible and the blue CHRG light bar with as many bars as possible.

I'm curious what Toyota thinks about using B all the time.

 

[Bassman]

Use B mode all the time to slow down at lights and going down steep hills. Just put it back in normal drive mode when I need to use the cruise control.

 

[waidy]

Like most of the Rav4ers in this forum, I only use B mode when I know I have to stop (for a stop light, stop sign, etc.) or on a long and windy downhill road (to slow down for sharp curves). When driving downhill on freeway, I use N or sometime I accelerate on a downhill freeway to pick up the speed for the upcoming uphill. It is because it uses less energy to speed up on a downhill then accelerate on a uphill. In another word, I seldom to use B mode on Freeway.

 

[Brandy]

I use B mode extensively for start stop driving, it helps by always braking when I take foot off accelerator when I do not want to use the brake. B mode is great for down hills also to control your speed with out using the brakes.

To me B mode is not so much for extending range but for taking off extra speed whether because of traffic or down hills.

=D~~Brandy

 

[user 8403]

B mode is less efficient than other modes.
I have 30k on my current 23prime. I have tested range etc on consistent commutes.
Bottom line is, “Generating electricity and storing it in the battery consumes / wastes 70-75% of the energy in conversion.”
Now of course if you can’t coast
To a stop then the 25-30% Regen is a nice bonus.
The most efficient way to is to modulate the accelerator peddle to the line between Regen and Eco. This is effectively Neutral, and costs and uses as close to 0 energy as possible.
Other back up… I have had 3 Prius (1) was a prime, a 22 rav4 Prime, and the BMW im40 e-drive that o got for my Wife.
On the BMW when in B mode the range drops 16miles at 80% starting charge. If I turn it
Off and on again in D then the 16 miles returns.
My Prius prime had a lifetime 100.6MPG when totaled. My max recorded range was 36.3 miles on the 22-25 mile expected range.
I have obtained a 53 mile EV trip in heavy traffic on my 22 R4Prime, and seen 52 mile on my 23 R4P. I like to be efficient, but not to hypermiler status.

 

[asavage]

Mike, your experience with B-Mode driving on a Prius is completely unrelated to B-Mode on the RAV4 EV.

Again, completely irrelevant.