Range Mode differences?

[livesmith]

Anyone know what Range mode technically does?
On my 15 S85D I've noticed playing with Scan My Tesla it seems to be RWD when cruising without Range mode and then switches to FWD with range mode on. I can't understand how that would save any energy?
I can understand on a performance model you might shift to a more efficient motor that way but not on mine?

It also mentions HVAC usage but I'm questioning what it actually changes?

And is it the LED eyebrow lights that it says it's turning off? Can't see how that would save anything appreciable. Also, it doesn't seem to actually turn mine off anyway. Maybe because of a DRL setting?

 

[brico84]

I don't have AWD, but my understanding is on AWD cars it distributes the work between the motors differently. I can't remember if it is 50/50 or 90/10 which is which way, but one of them is more efficient. Range mode enables that efficiency. You lose some "umph" in this mode if you hit the accelerator while cruising at speed with Range mode on, but I doubt it would be noticeable.

It also turns off your daytime running lamps and adjusts how it heats/cools the battery.

 

[aesculus]

It will also back off the cabin environmentals (heating and cooling) a bit.

Pretty sure it goes to single motor too (90/10 above).

 

[Cheburashka]

I've never really seen any measurable increase in range with range mode on my 75D.

I have seen it turn down battery conditioning so my car ends up charging slower at a supercharger.

Turning the DRL off probably gives an extra foot of range.

 

[Crutonius]

I've never quantified what range mode does to one's range. I think it's a lot less helpful than drafting based on my experience with an S 60.

 

[PCMc]

My understanding is that range mode does a combination of things.

Limits the amount of energy which the HVAC can draw. You likely would notice this most in cold ambient conditions when energy draw for the additive electric heating being limited. Under more moderate ambients not sure you'd notice much.

Does play with the balance of energy distribution between front and rear drive units on the AWD cars.

Alters how the battery packs are actively heated/cooled. In cold conditions it limits the active heating of the battery and relies more on waste energy from the motors and battery itself to warm it, but I believe also alters cooling and allows the battery to actually run a little warmer if it passively gets to those temps.

The only operating condition where I found range mode to really help was the case where my car sat outside in cold ambients and then had to do short drive cycles, like the 5 mile commute I had from my office to home. In that case turning on range mode would prevent expending energy to actively heat the battery which really had no value given by the time it was actually starting to improve regen I was at home and parking the car in my garage. I could directly see this benefit of range mode by the difference in the energy I'd see shown being consumed in my energy chart in the car and my trip Wh/mi values.

Outside of that specific operating scenario, I ended up concluding it was of no significant benefit and haven't used it for multiple years.

 

[aesculus]

On my 70k, 2016 Model X, 90D I get an extra 3-4% on a 150 mile mountain trip in the winter. It's a game changer for me since my battery has lost 10% of it's range. Note temperatures would be in the mid to high 30's F. A fair amount of that is probably not heating the battery at the start but often I even pre conditioned the cabin for 15 minutes with no where near the same effect as range mode.

 

[KalJoMoS]

I can concur to @PCMc, it does affects the car’s ability to heat and use the additional electrical devices. I have understood that using this on your AWD car will switch to rear engine, thus loosing AWD. I have also seen that it will give you app.3-5% of more range on long distance drive. You will charge a bit longer on the trips as the car will need to get the battery heated up for it. I use it regularly on wither periods as we have most of the time ambient temp. below freezing temperatures.

 

[brainhouston]

I have understood that using this on your AWD car will switch to rear engine, thus loosing AWD.

No, ur not loosing AWD. It only switches which drive unit used while cruising. During hard acceleration it uses both drives in any mode, i watched it with SMT.

PCMc nailed it.

I personally haven't tested difference in cold but in summer i noticed about 10-20Wh/mi increase with range mode off.
AC doesn't seem to be affected much according to SMT but PTC heater def decreases usage with Range On.

Most ppl on here agree that Range mode should be used on short cold trips, otherwise it doesn't really matter.
One other thing worth mentioning is Range Mode could be beneficial in cold due to decreased wear on battery heater, since those seem to burn up quite often.

 

[KalJoMoS]

I can say this has (using Range mode) become a habit on my winter drives over the years. Recently have found out that this function might be a way to get the promised EPA rating. I have compared few drives and in the area I drive only summer is giving almost similar results.

This is one recent, we do not have significant terrain so the trips are smooth. So much as I have tried to get good results it seems I’m still missing something. With this drive approximately 30 miles was on highway speed (around 70, the last section on the graph) and rest not above 60. And wind was somewhat at back. Here is the second part.