MYLR real world mileage?

[LeaveMeAlone]

Hi all, just took delivery of a MYLR in southern California. So far the car is amazing, but I took a road trip this weekend up the PCH/101 to the Bay Area and noticed significant differential between estimated and real world range. Granted I was going ~70-80 most of the time, so I know efficiency drops a bit at those levels, but was surprised to see actual vs. estimated differed by almost 150 miles, or ~50% of the battery capacity. Had to stop four times to supercharge vs. the originally-estimated one stop. Driving conditions were near optimal, windows closed, no A/C, not too aggressive on acceleration.

Is this abnormal? Anything I can be doing to get actual range closer to the advertised 326 at highway speeds? A little surprised and disappointed as the car is brand new. Sorry for the newbie question and thanks in advance for any input.

 

[anoldsole]

Your range going up the 5 at 65 on autopilot will be closer to the rated range. Going up PCH ate up my battery like crazy last I drove it but it's a fun road and it's hard to drive slow on it!

 

[jcanoe]

The EPA combine city/highway estimate of 326 miles is only useful when comparing different EVs. To achieve similar range you would have to drive at under 50 MPH, no AC or heat, over flat terrain, dry roads and no head wind.

If you are concerned about maximizing your range and efficiency you will have to drive slower, no faster than 70 MPH, with 65 MPH average speed. Or you can just enjoy the Model Y's amazing performance and technology and charge more frequently. Many first time EV owners assume that that they should charge the EV to 100% and then drive as far as possible before charging. The Tesla Model Y's built-in navigation system is also biased towards making fewer charging stops. A better approach is to plan on stopping to charge at a Supercharger about every 2 hours. The ideal Supercharger session would charge the Model Y's battery from below 50% state of charge (SOC), probably close to 20%, to no more than 70% SOC (80% maximum.) This will enable you to charge faster, get back on the road sooner. The objective is to charge so that you can reach the next Supercharger, not skip Supercharger stops along your route.

Many Tesla owners prefer to use ABetterRoutePlanner (ABRP) when planning road trips. ABRP is available as a web app and a phone app. ABRP enables you to configure multiple driving parameters (not just speed.) ABRP route planning generally plans for more charging stops along your route than does the Tesla Navigation software.

 

[TomServo]

ABRP is nice but doesn’t provide TURN by TURN directions, it just shows the time and distance to a SuoerCharger and how long you need to charge there. I’m trying to plan a route for an up coming trip and there are three “routes” I can take off I-64, am trying to avoid Richmond VA and DC over the Independence Day weekend. So I have to use Google Maps to plug in each Super Chargers address to see the actual roads since that takes me off I-64 onto state roads to get to my destination in southern Maryland.

 

[Clark_Kent]

You should probably go by Wh/mi as it's an easy number for owners to look up and it's a better indication of consumption. The three main killers of range are speed, elevation, and ambient temperature. Going 80 mph, or anywhere near it, on your trip did not help. There's a chart on Teslike illustrating the impact of speed on range and it's eye opening.

For comparison, I have about 6,900 miles on my MYP and my lifetime Wh/mi is 275 or about 285 miles of range. That puts lifetime efficiency over 90%.

 

[Saxgod]

On our way home from SA to VCT we averaged 411 wh/mi. It was 96 degrees outside and ac was cranked for third row passengers. Same or lower efficiency as my 2014 P85.

 

[naD alseT]

People tend to under estimate the effect of speed on energy consumption. A general rule is to take the speed at which you get your rated range (call it 50 mph for a tesla), and use this formula to guesstimate the drop Range*50^2 / mph^2.
So at 80 mph, it's 324*(50*50)/(80*80) or 324 * 0.39. So you should get about 40% of your rated range.
Add on the fact that no one starts at 100% battery and no one drives until 0% battery (let's say you go from 90 to 15%)...
Now your real world range at 80 mph is 324*(0.90-0.15) * (50*50) / (80*80) = 243 * 0.39 = 95 miles.
This is true for any vehicle, but ICE engines are so inefficient in the first place, the 'loss' from a speed increase is not as noticeable.
For a Tesla, there is almost no other energy 'losses', so the wind resistance 'loss' is THE most important factor (the dang thing has like 6 moving parts!!)
Just wait until the Ford Lightning launces...300 miles of range my a@@! That parachute at 80 mph is probably going to get 80 miles of range!

 

[LeaveMeAlone]

This is all super helpful. Thanks everyone. So the takeaway is range drops nearly exponentially above 65. That's tough - I wonder what the assumed speed is on the Tesla route planner when they build in supercharging stops.

 

[Saxgod]

This is all super helpful. Thanks everyone. So the takeaway is range drops nearly exponentially above 65. That's tough - I wonder what the assumed speed is on the Tesla route planner when they build in supercharging stops.

Don’t forget AC load. The ac full blast drains some serious power.

 

[jcanoe]

This is all super helpful. Thanks everyone. So the takeaway is range drops nearly exponentially above 65. That's tough - I wonder what the assumed speed is on the Tesla route planner when they build in supercharging stops.

The Tesla Navigation system takes into account the speed limit of the roads on the travel route, also elevation changes but not road conditions, weather, temperature, traffic or head winds.

 

[bluenycom]

So the takeaway is range drops nearly exponentially above 65.

This is true for all vehicles, not just EV. Why do you think the national speed limit was 55 in the 70's? It was not for safety reason.

 

[jcanoe]

This is all super helpful. Thanks everyone. So the takeaway is range drops nearly exponentially above 65. That's tough - I wonder what the assumed speed is on the Tesla route planner when they build in supercharging stops.

This CleanTechnica article shows the impact of speed on the power utilization, range for the Tesla Model S, Model X. The values would be different for the Model Y but the curve would be close to the curve for the Model X. Increasing the speed of the Model X from 60 MPH to 80 MPH reduces the estimated range by ~25%.

Tesla Range Plotted Relative To Speed & Temperature (Graphs)

 

[DayTrippin]

Easy way to look at it. Aerodynamic drag goes up the by the square of speed. So a 10% increase in speed results in 1.1 x 1.1 = 1.21 or 21% more drag for a 10% increase in speed. That is only part of the equation and only focused on the drag, not the power required.

The power required goes up by the cube of speed. So a 10% increase in speed results in 1.1 x 1.1 x 1.1 = 1.33or 33% more power required to go 10% faster. Parasitic drag such as rolling resistance is more linear. As you can see the amount of power required can go vertical pretty quickly if you were to look at it on a graph. It will take more from your energy source (gas or electron) to provide the power you need.

So to go fast, and do it efficiently, is why aerodynamics matter so much and while I've always appreciated what Tesla brought to the table. Their focus on aerodynamics always was the right approach. I was an aeronautical engineer in my former life until I found a better way to pay the bills. Sadly Tesla does a worse job at meeting their ratings in the real world compared to what I've seen other companies do. The MME typically meet or beats its rated EPA range on the road it is pretty damn rare for most Teslas to meet theirs. From what I've seen with the Taycan, it easily beats its range.

Here is a great primer about drag.

Aerodynamic Drag – The Physics Hypertextbook

Drag is the friction from fluids like air and water. A runner feels the force of aerodynamic drag. A swimmer feels the force of hydrodynamic drag.

physics.info

 

[LeaveMeAlone]

People tend to under estimate the effect of speed on energy consumption. A general rule is to take the speed at which you get your rated range (call it 50 mph for a tesla), and use this formula to guesstimate the drop Range*50^2 / mph^2.
So at 80 mph, it's 324*(50*50)/(80*80) or 324 * 0.39. So you should get about 40% of your rated range.
Add on the fact that no one starts at 100% battery and no one drives until 0% battery (let's say you go from 90 to 15%)...
Now your real world range at 80 mph is 324*(0.90-0.15) * (50*50) / (80*80) = 243 * 0.39 = 95 miles.
This is true for any vehicle, but ICE engines are so inefficient in the first place, the 'loss' from a speed increase is not as noticeable.
For a Tesla, there is almost no other energy 'losses', so the wind resistance 'loss' is THE most important factor (the dang thing has like 6 moving parts!!)
Just wait until the Ford Lightning launces...300 miles of range my a@@! That parachute at 80 mph is probably going to get 80 miles of range!

"parachute" well said! The formula makes a lot of sense and is essentially what I experienced coming up the PCH at 70-80mph - about 0.4x real vs. estimated range.

Easy way to look at it. Aerodynamic drag goes up the by the square of speed. So a 10% increase in speed results in 1.1 x 1.1 = 1.21 or 21% more drag for a 10% increase in speed. That is only part of the equation and only focused on the drag, not the power required.

The power required goes up by the cube of speed. So a 10% increase in speed results in 1.1 x 1.1 x 1.1 = 1.33or 33% more power required to go 10% faster. Parasitic drag such as rolling resistance is more linear. As you can see the amount of power required can go vertical pretty quickly if you were to look at it on a graph. It will take more from your energy source (gas or electron) to provide the power you need.

So to go fast, and do it efficiently, is why aerodynamics matter so much and while I've always appreciated what Tesla brought to the table. Their focus on aerodynamics always was the right approach. I was an aeronautical engineer in my former life until I found a better way to pay the bills. Sadly Tesla does a worse job at meeting their ratings in the real world compared to what I've seen other companies do. The MME typically meet or beats its rated EPA range on the road it is pretty damn rare for most Teslas to meet theirs. From what I've seen with the Taycan, it easily beats its range.

Here is a great primer about drag.

Aerodynamic Drag – The Physics Hypertextbook

Drag is the friction from fluids like air and water. A runner feels the force of aerodynamic drag. A swimmer feels the force of hydrodynamic drag.

physics.info

Really great way of thinking about it. Thanks for the mini primer. Assuming 50mph base (per above), I was traveling at 80mph, or 60% "over" --> 2.6x drag --> 4.1x power requirement. But I don't think real vs. estimated range would scale linearly from there (i.e., 4.1x--> 0.24x real vs. estimated range seems extreme). Do you have a rule of thumb for reconciling? Is it not the case that mileage estimates are re-calibrated in real time to reflect driving patterns and weather conditions?

Thanks again everyone, this has been really helpful (albeit a disappointing reality check).

 

[mark95476]

I'm doing my usual fun drives where I go up and down 2500 mountains twice, freeways at 70+ mph, ...etc...

- Real-world 232 Wh/mi avg over ~68 miles
- Guess O Meter (computer) estimated range of ~240 miles at 54% SoC

 

[DayTrippin]

"parachute" well said! The formula makes a lot of sense and is essentially what I experienced coming up the PCH at 70-80mph - about 0.4x real vs. estimated range.


Really great way of thinking about it. Thanks for the mini primer. Assuming 50mph base (per above), I was traveling at 80mph, or 60% "over" --> 2.6x drag --> 4.1x power requirement. But I don't think real vs. estimated range would scale linearly from there (i.e., 4.1x--> 0.24x real vs. estimated range seems extreme). Do you have a rule of thumb for reconciling? Is it not the case that mileage estimates are re-calibrated in real time to reflect driving patterns and weather conditions?

Thanks again everyone, this has been really helpful (albeit a disappointing reality check).

TBH, it can be hard to reconcile exactly. I used to be so anal about this in my former life. I had access to wind tunnels and modeling tools and anytime I could sneak my own stuff into play, I did. Thankfully I never got caught.

The problems we have here are several. The drag coefficient can change at different speeds, how the wind is hitting the car and so many other variables. Let's go back to our basic 50 mph baseline. If we see the energy consumption at that speed from inside the car, we don't know how much of that is comprised due to aerodynamic drag and parasitic (bearings, tire rolling resistance, etc.) Given how good the drag coefficient is, you might be surprised how low the aero drag is on a Tesla.

I used to have a Honda Insight. A very aerodynamic car especially in its day (0.25). This thread will help you a lot. A lot applies to a Tesla. Look at the observed HP numbers at 50 mph and 70 mph in this thread.

How much power to maintain speed?

How much power is reqd to maintain an Insight at 30mph on the flat in good calm conditions? BHP? KW? Assume tyres at say 50psi. Any offers?

www.insightcentral.net

 

[TomServo]

Speed kills. Having owned 3 Volts since March 2012 EPA rated at 38 and 53 miles respectfully, one learns the simple truth of how far those electrons will take you and what impacts them the most. New Volt owners when they would come to the various online forums would be SHOCKED they couldn't get anywhere near the EPA-rated range.

They were introduced to the Three T's: Temperature, Terrain, and Technique and how they impact the "rated range" then they were told that EV operate in reverse to a traditional ICE vehicle when it comes to efficiency. In an ICE vehicle, one can easily meet or exceed the EPA highway ratings while an EV get's WORSE range at highway speeds and the reverse is true in slower urban/city driving. My last ICE vehicle was a 2017 GMC Acadia V6 rated at 25 mpg highway, I could easily get 29 mpg at freeway speeds keeping UP with traffic (hand calculated). My last Corvette was a 2014 Stingray rated at 25 mpg highway and again I could easily get 29 mpg. On the other hand, my 2020 Tesla LR AWD Model Y rated at 316 miles by the EPA I'm lucky to get 260 miles at highway speeds, but the truth is no one operates an EV from 100% SoC to ZERO. Most likely you only use about 80% of its available power and that's because of the charging network. It's not like there is a DCFC charger at every exit on our interstate system. I ran my GM cars down to where the Trip Computer stopped displaying available range as I knew I could since they banked 2 or more gallons and that there was a gas station at the next exit.

I really believe NEW EV owners should be given a primer on how EV's operate and how to manage the available power contained in the battery pack.

But owning a small battery car like the Volt was a great education and I believe I know how to extra the most range from my Tesla's battery.

 

[Grindy2424]

Just picked up my model Y and drove from PDX to Bellingham with 110 temperatures.

I lost approximately 34% battery efficiency doing 65-75 and running AC at full blast with kids.

Seems normal based on this post?

I heard about 20% loss at 95 degrees as well in real world.

anyone verify these numbers?

 

[whisperingshad]

Honestly doing 80 on the freeway will get ya around 200ish miles

 

[DayTrippin]

I am beginning to think longer range EVs are like Goldilocks. Can't be too hot, or too cold. Can't charge too high or let it go too low or your battery will suffer. Running AC or heat will knock that down as well. Basically take whatever the rated range of a Tesla, cut it in half, and you likely won't be disappointed. Assuming it isn't too hot or too cold...

This is our first Tesla, and our first really long range EV (>100 miles). I told my wife to go for the longest range one to be safe and to comfortably be where we want to be. I really wanted to go with the M3. She wanted the MY. We got the MY. Won't say I am regretting it as I love the car, but I think real world we are looking at 160-180 miles realistically if we play like Goldilocks with our car and to not over charge, run too low, run the AC on super hot days and still have a bit of a buffer. Most of the traffic on the highways is running 80.

I wish you could tow with the Model S in the US (with no potential warranty impact) as and we likely wouldn't have bought the MY. I don't like the MX so that wasn't even an option. So I can't wait for our MS to get here so we can have a pretty good range without sweating it. Doesn't help that Tesla can't really seem to make their EPA numbers for most people but some other companies seem to do better. Maybe with all the competition, things will get better for everyone.