Am I Supposed To Be Getting Better Range Than This?

[AlanSubie4Life]

I just went and looked at your drive length. It took you 23 minutes to drive four miles. That is just 10mph. If you run the AC at all that has a huge impact. Or any other use previously mentioned. Any fixed load factor gets divided by vehicle speed to add to your Wh/mi, so low speeds are bad for those factors (high speeds are VERY bad for aero!).

For example, for 2kW (it can easily be this high when cooling the car initially, and can be over 4kW in some circumstances), that would add 2kW/10mph = 200Wh/mi.

 

[therealjimbob]

I just went and looked at your drive length. It took you 23 minutes to drive four miles. That is just 10mph. If you run the AC at all that has a huge impact. Or any other use previously mentioned. Any fixed load factor gets divided by vehicle speed to add to your Wh/mi, so low speeds are bad for those factors (high speeds are VERY bad for aero!).

For example, for 2kW (it can easily be this high when cooling the car initially, and can be over 4kW in some circumstances), that would add 2kW/10mph = 200Wh/mi.

So today I drove my son to school. I used the energy graph and this is what I got. About halfway through the trip I shut the heat off and I never went over the speed limit.

 

[therealjimbob]

So today I drove my son to school. I used the energy graph and this is what I got. About halfway through the trip I shut the heat off and I never went over the speed limit.

Also the trip was about 10 miles and on the 15 mile graph it starts right after that very large peak at around the 10 mile marker.

 

[Regaj]

Lots of up and downs. That's what you'd expect with a trip like that.

Short trips like a trip to your local school aren't going to tell you much. You're stopping and starting and accelerating from low speeds... actions which consume great gulps of energy. And, yes, if your normal use of the car mostly involves those kind of short, stop-and-start trips you're not going to see the greatest efficiency.

Find a long, flat road, turn on cruise control, and you'll get a different story.

 

[AlanSubie4Life]

So today I drove my son to school. I used the energy graph and this is what I got. About halfway through the trip I shut the heat off and I never went over the speed limit.

Admittedly I never use the energy graph (it’s basically useless except for figuring out your battery capacity and seeing basic things like you are using it for), however, I can’t make sense of some of this:

It looks like they apply a different averaging window depending on whether 5mi or 15mi is chosen, since the 5mi plot does not look like a portion of the 15mi plot. And these pictures were taken at the same time.

Anyway this all seems normal. No idea where you are but if there are hills or stop and go this is very normal. (Obviously don’t use the brakes!)

At that temp differential you will see substantial difference between heat and no heat.

As mentioned, measure round trips using the trip meter. Do them entirely with the heat off (warm the car before leaving to make it comfortable). If you have hills there could easily be net elevation gain which makes a huge difference, so have to look at round trip.

 

[jjrandorin]

So today I drove my son to school. I used the energy graph and this is what I got. About halfway through the trip I shut the heat off and I never went over the speed limit.

I think many have said this, but efficiency over short periods is basically meaningless to look at. In your screenshot it shows "5 miles" as the graph.
that is not going to give you anything meaningful in relation to this topic, whatsoever. If two of your earlier trips were to the supercharger, does that mean you dont have a place to charge at home or work and are depending on suppercharging?

If thats the case, people who buy a tesla in that situation many times think some variation of "Oh the car has a 250 mile range, I only drive 20 miles a day, so I will just need to charge it up every 10 days or so, that wont be so bad". Then, they buy the car, and start focusing on "hey wait a minute, I only drove 8 miles to various stores yesterday, why did the battery meter roll off 15 miles?" Or.... "I thought I was going to only need to charge this car every 10 days, but I am only getting 130 miles of range on a charge, not 250, and I have to charge every 4-5 days, not every 10 days, my car is broken, right?"

If you dont have charging you can plug into at home, and were expecting to only charge the car every XX days because "it has a 250 mile range and I only drive XX miles a day" its not going to work like that.

 

[AlanSubie4Life]

Short trips like a trip to your local school aren't going to tell you much. You're stopping and starting and accelerating from low speeds... actions which consume great gulps of energy. And, yes, if your normal use of the car mostly involves those kind of short, stop-and-start trips you're not going to see the greatest efficiency.

There’s no reason you can’t have extremely excellent efficiency on such a trip - as long as you do not need to run heat/AC. It’s nearly optimal; the only thing better is going a steady 19mph.

Accelerating matters very little - as long as you regen as little as possible and don’t use the brakes.

About halfway through the trip I shut the heat off

What year is the vehicle (heat pump or not?)? Seems likely to be resistive heating but not clear. Makes a bit of a difference for heating. Regardless, short trips will always be bad for the impact of heat.

 

[bedoig]

...as long as you do not need to run heat/AC...

Says the guy from San Diego

 

[AlanSubie4Life]

Says the guy from San Diego

Yeah, if you have to do that, drive FAST. And also for a long distance. Definitely lucky down here.

 

[therealjimbob]

Hey @AlanSubie4Life,

So in all honesty today was a whole lot better. I think I’ve been driving this car wrong. When I drove it today I paid more attention to the energy graph and when I did my average was like 220 wh with the heat on.

Also can you explain what you mean by

“Accelerating matters very little - as long as you regen as little as possible and don’t use the brakes.”

I would think I would try to regen as much as possible, am I wrong to assume that?

Also does acceleration have that little effect on the battery? Should I try to reach optimal speed as fast as possible or as slow as possible? I know with my hybrid it did better when I would accelerate slowly.

Thanks for you post.

 

[jjrandorin]

I would think I would try to regen as much as possible, am I wrong to assume that?

Thats a normal assumption, but yes you are wrong to assume that. If the goal is lowest use of energy possible, its better to drive such that you are basically moving at as much of a constant speed as possible. A lot of regen means that you had to accelerate, then brake (regen) to slow down.

Its pretty normal for new tesla owners to jackrabbit forward, then regen brake, then jackrabbit forward, then regen. Thats better than jackrabbiting and then using the brake, but its not better than not jackrabbiting and "gliding" everywhere.

Note that I am not saying you or anyone else needs (or even should) drive that way, unless you are trying to hypermile / be as "efficient as possible". Its better to just "drive" and enjoy the car.. unless that isnt the goal.

 

[AlanSubie4Life]

Also does acceleration have that little effect on the battery?

Yeah doubt it matters much.

Should I try to reach optimal speed as fast as possible or as slow as possible? I know with my hybrid it did better when I would accelerate slowly.

Lower average speed is better for aero. But you lose energy if you regen. Hard to say which is more optimal.

I say do not use regen if you can, because it is not 100% efficient. Better to coast to a stop (neglecting aero effects mentioned, which of course you also don’t get back…so maybe regen at higher speeds is the right call).

But for sure don’t use the brakes unless of course you need to. Regen if you need to!

“Accelerating matters very little - as long as you regen as little as possible and don’t use the brakes.”

The drivetrain efficiency does not seem to change much with power output. I’m not saying it doesn’t matter - just matters very little. Probably lower power output is slightly better but it’s likely a small contributor to overall results. So I would not worry about fast acceleration - as long as it does not subsequently result in braking or excess regen (which it often does if not carefully anticipating and planning your coast).

 

[KenC]

So in all honesty today was a whole lot better. I think I’ve been driving this car wrong. When I drove it today I paid more attention to the energy graph and when I did my average was like 220 wh with the heat on.

Also can you explain what you mean by

“Accelerating matters very little - as long as you regen as little as possible and don’t use the brakes.”

I would think I would try to regen as much as possible, am I wrong to assume that?

Also does acceleration have that little effect on the battery? Should I try to reach optimal speed as fast as possible or as slow as possible? I know with my hybrid it did better when I would accelerate slowly.

Thanks for you post.

I think I read somewhere that regen is only about 70% efficient; so trying to maximize "unnecessary" regen just for regen sake is not more efficient. Of course, there's necessary braking, and you want to maximize regen when doing that.

 

[garth_angst]

Trip A and B are pretty much my lifetime stats. I only owned the car for 3 days now

YOUR lifetime stats, but what are the stats for the full 44,000 miles on the car or were they erased? I'm interested to to see if the previous driver was super aggressive or not.

 

[therealjimbob]

YOUR lifetime stats, but what are the stats for the full 44,000 miles on the car or were they erased? I'm interested to to see if the previous driver was super aggressive or not.

Unfortunately they were erased. I would have liked to known that too.

 

[therealjimbob]

Thats a normal assumption, but yes you are wrong to assume that. If the goal is lowest use of energy possible, its better to drive such that you are basically moving at as much of a constant speed as possible. A lot of regen means that you had to accelerate, then brake (regen) to slow down.

Its pretty normal for new tesla owners to jackrabbit forward, then regen brake, then jackrabbit forward, then regen. Thats better than jackrabbiting and then using the brake, but its not better than not jackrabbiting and "gliding" everywhere.

Note that I am not saying you or anyone else needs (or even should) drive that way, unless you are trying to hypermile / be as "efficient as possible". Its better to just "drive" and enjoy the car.. unless that isnt the goal.

That’s good to know. I have noticed that over the last couple days I am learning the cars quirks and I am getting better at keeping my energy consumption within the normal range.

I will say one thing though, minus the safety score anxiety this car is super fun to drive when you get the hang of it.