I think the biggest thing that's under your control is speed. Aerodynamic drag increases in proportion to the square of the velocity. So if you drive at 70mph instead of 60mph (for example), your speed is 17% higher but your drag is 36% higher (70/60 = 1.17, and 1.17 x 1.17 = 1.36). So small increases in speed can reduce your range by a lot, and small decreases in speed can increase your range.

Anything that increases drag, e.g. bikes mounted on the roof, or towing a trailer, will have a disproportionate effect.

All of this also affects ICE vehicles the same amount, but most people are unaware of it because they don't have a large range readout to reinforce their latent range anxiety.

 

Look at this, cars see up to a 28% reduction in fuel economy with a bike rack. That's dramatic.

How Bike Racks Affect a Car's Fuel Economy

To find out how bike racks affect a car's fuel economy, Consumer Reports tested a roof rack and a trailer-hitch rack loaded with two adult-sized bicycles on a 2019 Nissan Altima and a 2019 Toyota RAV4 going 65 mph.

www.consumerreports.org

 

I all depends on the driving situation you're in. Drag matters most at freeway speeds, which is when range also matters the most (because you're more likely to go long distances if you find yourself on the freeway). So I agree with O's comments above. Other things:

Around town (when efficiency matters less because range is less of a concern), i.e. at speeds where drag matters less, your driving style makes a big difference. If you always punch it off the line and brake hard to slow down your efficiency drops a lot.

Going uphill takes a lot of energy (90% of which you'll get back on the way down, assuming same speed). Lifting an R1S with 100 kg of driver and stuff for 1000 ft takes 2.7 kWh, or about 2.15% or your usable capacity of a large battery pack (which I assume to be ca. 125kWh). So if you drive to the mountains from sea level to say Lake Tahoe (ca. 6000 ft) it'll cost you an extra 13% of battery (more if you're loaded up with stuff).

Towing is stupidly expensive.

Resistive heating takes a lot of energy, more than AC. Plus on warm days when you use your AC your battery is also nice and warm, and you have more juice in the tank compared to cold days. In my I-Pace the heater can pull as much as 6kW, though once the cabin is warm it's less than that. But it makes a difference ... one hour of heating at say 4kW is 4kWh, or 5% of my I-Pace's usable battery capacity.

Seat heaters / coolers use a lot less than cabin heat / AC ... almost negligible.

Radio, lights, etc are negligible.

 

Going uphill takes a lot of energy (90% of which you'll get back on the way down, assuming same speed).

no sorry, but you will not get 90% back coming down hill. Not even close.

 

Recently viewed a YouTube video on an Out of Spec range test on the R1T. Very informative. You may find it helpful.

 

Speed, temperature, wind, hills. Drive through 80 degree weather on relatively level freeways and maintain 55-60 MPH (often the flow of traffic in L.A.), and your range will likely be close to EPA figures. However, if you head out to Arizona in winter on a cold night (high 20's or low 30's), dealing with some of the steep hillsides that exist, common desert head-winds and keep up with the common flow of traffic on wide open desert freeways at 80 MPH and you'll likely end up with about 55-60% of the rated range. Slap a trailer on it and you'll be fortunate to make it 100 miles on a full charge. Without the trailer, probably in the 170 to 190 mile range. Likewise, if you end up on a basically level side road in good weather (over 70 degrees) with no wind at a steady pace of around 40 MPH, likely would get in the 400 mile range, without AC on.
Also, per manufacturers, wheel size impacts range. Naturally, if the truck is loaded to capacity, that will impact range too. Tonneau cover open will likely create drag and impact range. Lower ride height on highways will improve range. Using the Heater sucks up A LOT of battery. AC, not quite as bad. Tire pressure. If you go off-roading a lower your pressure down into the 20's or 30's, will adversely impact your highway range versus the recommended pressure at around 48 psi.

The list goes on and on. So many things can impact range. Those are the most common ones. When travelling, I always plan my trips based on about 60% as I'm not one that wants to drive conservatively (hyper-mile). I want to drive like I would in any other vehicle. So, my rule of thumb for long highway trips is around 60% of rated range and I'm usually pretty close.

 

Of the potential energy that is required to lift the weight you will get ca 90% back. Of course you won't get the energy back that you used to travel the associated distance. In other words, if you use 10kWh "extra" to lift the car X number of feet, you'll get about 9kWh back when you drop the car the same number of feet.

 

Not even close if you are talking about regen braking to get used energy from the battery during the uphill back on the downhill. I’ve got 8 years in teslas in Alaska. From my house to “town” I descend ~800’ over about 4 miles and my drive to work is 7 miles top speed 45 mph. In my current model 3 LR most days I average ~325 Wh/mi round trip, use 1-2% driving to work and 4-5% going home. On flat ground same driving type I’m more like 225-240 Wh/mi.

under full regen you at best get 50% back. That is under full force regen. Going down Hatcher pass 2800’ in 15 miles I can gain 1-2% but lose 10-15% going up.

Now from what I find effects range.
Like others have said speed is #1. ICEs tend to be more efficient on the highway. EVs are more efficient around town. In the teslas I can get rated range or better running 55-60 mph. 65-70 10-15% range reduction, 70-75 more like 20-25% reduction.

up hill, like mentioned uphill is a huge hit.

cold weather. I don’t notice any real reduction in cold aside from running the heat. Sunny day clear roads 20F heat off I easily get rated range.

running the heat, It depends. First off EVs never feel warm and cozy inside when compared to an ICE. Keeping the heat set at 60-62F, I don’t notice much of a difference until if gets <0F. <0F like 25%, when it gets down to -20-30F more like 40-50%. But at those temps there are multiple factors contributing. Now if you crank the heat to 70+ Even with temps in the 20’s it can cut range by 25-40%.

headwinds make a large difference. 30-40mph headwind can cut range by 30-40%

snow covered roads. Lose fresh snow can cut range by 50%.

rain, rain that is enough to wet the roads can cut range by 20%. Heavy rain more like 40-50%.

Snowing, loose fresh snow, temps <0F, I’ve had days where I average 900-1000+ Wh/mi. That is like a 75%range reduction.

that said I’ve had teslas in Alaska for 8 years and prior to last November my closest supercharger was >2000 miles from my house. Never run out of battery.

 

In this video, the biggest factor for their range would be the tire pressure setting. I thought he said in an earlier video the recommended tire pressure was 48 psi. In this video, he stated he set the tire pressure to 38 psi. Couple that with that they ran with the 20" AT tires and wheels, those would be the biggest hitters for the decreased range on this test.

So in summary, if you want 314 miles, get the 21" aero wheels + tires, maximize the pressure setting, and keep weight and accessories to a minimum. You should be able to get it.

 

Cold weather will reduce range versus 80dF by 25%-33%; driving into a strong headwind; higher average speeds; towing a trailer; having a roof box on the vehicle; all of the above will reduce the EPA ratings, some markedly.

 

As a 5+ year Model S owner, my best advice to you is to forget about all the various impacts wind, rain, snow, etc…. can have on the vehicle. Over the long term just count on the vehicle being able to deliver a worry free driving range somewhere around 55-60% of the rated dash range. Yes you will have days that vastly exceed this, but the novelty of plotting a travel course like you’re flying a single prop Cessna really loses its luster over time. I still fall into the trap of looking at the weather conditions all along my route, pushing the limits to see if I can make it and each time I pull into a SC with 5mi on the dash I tell myself I’m never doing it again (and no I have never been stranded).

My wife just did a 650mi round trip route in our Model S yesterday and it took her a little over 14hrs of driving/charging. She too was worried about how much to charge at each SC so I just gave her a list of stops, included the miles to the next SC, and gave her a dash range to charge to that was 40% higher than the actual mileage to the next SC. She made the entire trip with no range anxiety. Stopping to charge 7 times I think created a little anxiety but she has a fun story to tell and can brag that she holds the record in our house for most miles traveled in a day in our car .

Range is king. Give me my Max Pack

 

As a 5+ year Model S owner, my best advice to you is to forget about all the various impacts wind, rain, snow, etc…. can have on the vehicle. Over the long term just count on the vehicle being able to deliver a worry free driving range somewhere around 55-60% of the rated dash range. Yes you will have days that vastly exceed this, but the novelty of plotting a travel course like you’re flying a single prop Cessna really loses its luster over time. I still fall into the trap of looking at the weather conditions all along my route, pushing the limits to see if I can make it and each time I pull into a SC with 5mi on the dash I tell myself I’m never doing it again (and no I have never been stranded).

My wife just did a 650mi round trip route in our Model S yesterday and it took her a little over 14hrs of driving/charging. She too was worried about how much to charge at each SC so I just gave her a list of stops, included the miles to the next SC, and gave her a dash range to charge to that was 40% higher than the actual mileage to the next SC. She made the entire trip with no range anxiety. Stopping to charge 7 times I think created a little anxiety but she has a fun story to tell and can brag that she holds the record in our house for most miles traveled in a day in our car .

Range is king. Give me my Max Pack

Well said. Range is King.

GO MAX PACK.

 

Why seven charging stops for 650 miles in a Model S? Four should have done it with no sweat broken unless there were highly unfavorable conditions (or the battery is severely degraded, or she drove it like she stole it)

Max Pack (vs large pack) won't help with total amount of time spent charging unless you're in a sweet spot where you're able to skip one charging stop compared to Large Pack, and then the difference in total time spent won't be large. That's because the amount of time you use for charging is dependent on how much energy you used, and not on how big the vessel is that holds the energy.

For those who question how much potential energy one 'gets back' going downhill after going uphill the same vertical distance: if there were no loss due to inefficiencies you'd get back 100%. That's just physics. I don't believe that Tesla's motors are so inefficient that they only get 50% back ... get back to me with the Tesla numbers once you have sat down and recorded multiple trips of the identical route with exact numbers of energy consumed in kWh and some plain algebra to give me a percentage ... I've done it with my I-Pace on multiple routes and the empirical number is 90%. Which is consistent with first principles and the approximate efficiency of electrical motors and battery charging.

 

you are thinking of the very basic science of it in terms of KE and PE. Like EVs are perpetual motion vehicles, which they aren’t. You are saying that I could go 100 miles uphill then on the way back down get 90 miles for a net using 10 miles for a 200 mile trip. Absolutely no way. If so why not just drive up and down hills all day to increase range? You get much better Wh/mi on flat roads then going up and down. Also most conditions of you completely let off the accelerator to get full power regen you will stop even if fairly steep grades. I think Tesla quotes~70% is max effect, but typically to modulate to the correct speed I’m only using 25-50% of that 70%.

in a few weeks when I take my winter tires off and switch regen back to full (I run regen in low all winter) I’ll get in my Tesla and drive up to prospect heights then down to Anchorage and post pictures of the energy graph from both trips and the round trip.

 

Haha you guys are funny. Lack of evidence trumps truth, eh?

 

No KOOL-aid drinkers here.

 

I climb 1,050 ft. and just under 3 miles from the valley floor to my house at 8,600 ft, using just under 10 miles of range going up, and I 'recapture' about 4 miles of range going back down.

 

That's a fantastic anecdote. The 4 miles of regen give you a net range loss of 6 miles for the 6 miles you travel, as if you'd just driven 6 flat miles. If you didn't have regen on the way down you would have spent 10 miles of range on 6 miles of distance. In other words, you recaptured all the potential energy that you spent on the uphill. I suspect that you didn't actually get all of it back (because there is some loss) but it's very close. 🍻

 

Tess only drinks that fancy elon water.

 

Lol. Perfect. Elon Juice

 

As someone who does a lot driving in WY, I will say that wind can be a huge factor. It was in my Tesla, and I expect it to be even more so in the Rivian since it it far less aerodynamic than a Tesla sedan. It’s something you should look at when planning any longer road trip with head or tail winds exceeding 10mph, as it can have up to a 30% impact on range. Obviously, as others have stated, having stuff mounted to or pulled behind your truck will only compound the impact.

 

the main issue is you are arguing basic science concepts with people like me with years of real world driving in Teslas. I had an S for 4 years (sold it in 2018) and 50k miles and now I’m almost at 4 years and 45k miles in the 3.

All of us with teslas are saying the same thing: Regen adds little to range even going downhill. Your arguments remind me of my son when he was an early teen.

and regen low vs regular does make a difference. When I’m in regen low I have to use the friction brakes more therefor not getting that energy back.

 

To remind you, this discussion originated with dismissive comments by another forum member in response to my statement that regeneration recaptures energy on the downhill, which is a fact.

If you think that I have no experience with EVs or that I behave like a recalcitrant teen I invite you to go over to Jaguar I-Pace EV400 Forum and see what I do there.

 

To remind you, this discussion originated with dismissive comments by another forum member in response to my statement that regeneration recaptures energy on the downhill, which is a fact.

If you think that I have no experience with EVs or that I behave like a recalcitrant teen I invite you to go over to Jaguar I-Pace EV400 Forum and see what I do there.

Please people. Stop fooling yourselves about Regen. It’s helps slow the car in city traffic. That’s about It.

 

Stop spreading misinformation

 

seriously? That’s your attack.

get a clue.

 

Here you go. I left my house set the cruse control to 40 mph, set regen to regular, turned the heat off and drove 5 miles and ‘730 vertical feet down. Then turned around and drove back. Going down Got 210 Wh/mi for a total usage of 1.05 kWh. Going back up I got 411 Wh/mi for a total of 2.055 kWh. Over the trip I got ~20% over rated range at 310 Wh/mi. Then just for kicks set regen back to low did the same trip down trying to modulate and use regen as little as possible and got 139 Wh/mi. Did better when I ignored the speed limit and costed more then used regen. Pretty far from the PE, KE prediction of getting 90% back, if so my trip down the hill with full regen would have netted me a fairly amazing -370 Wh/mi For an unbelievable ~5 Wh/mi over the entire trip.

Why don’t you find a hill and drive your ipace up and down to see what you get?

 

Here you go. I left my house set the cruse control to 40 mph, kept regen to low, turned the heat off and drove 5 miles and ‘730 vertical feet down. Then turned around and drove back. Going down Got 210 Wh/mi for a total usage of 1.05 kWh. Going back up I got 411 Wh/mi for a total of 2.055 kWh. Over the trip I got ~20% over rated range at 310 Wh/mi. Then just for kicks set regen to low did the same trip down trying to modulate and use regen as little as possible and got 139 Wh/mi. Did better when I ignored the speed limit and costed more then used regen. Pretty far from the PE, KE prediction of getting 90% back View attachment 5197
View attachment 5198

Thanks for the data! though I don’t now that is what sciencegeek was saying exactly. I think he is just claiming the 90% on PE recovery only. What is the weight of your vehicle? Also does you car blend in regen when you press on the brake? I know there are other complications like whether the battery is full or cold….

 

We're talking past each other. How much does your car weigh with you in it?

 

(Corrected cuz I can’t do math it seems)…actually I just realized that for 2000 kg and 700ft the PE change is approx 1kWh.

so your experiment, @ColeAK proves @sciencegeek ‘s point. That’s because you ended up getting the average efficiency over the course of the uphill and downhill combined trip. If you weren’t recovering PE almost completely (m*g*dh) then this would not have been true and you would have been “robbed” 1kWh over the 10 mi round trip. (Someone check my math please)

the consequence of high PE recovery is that you can assume your range will not be much impacted by topography along the way as long as you start and stop at the same altitude (potential)

this is not all due to regenerative braking. Some of it is due to converting PE to KE by coasting as you saw. So an ICE car will recover some PE as well, it just won’t be as high.

the reason this got me interested is that for a 3200 kg Rivian loaded with people and gear climbing 6000ft then descending 5000ft, this becomes pretty relevant. That is similar to a day trip we like to take here and the Rivian would be great for it.

 

…actually I just realized that for 2000 kg and 700ft the PE change might be tiny relative to the total energy expanded for that trip…

700 ft with 2000kg => 1.2 kWh
I think an M3 weighs a bit less than 2000 kg usually?

 

For the entire round trip I got 310 Wh/mi. Car is rated to range at 250wh/mi. So doing this loop over and over would reduce my range by 20% from the rated 310. I’ll add that around town at <50 mph I consistently get more like 215-225 Wh/mi, or 10% better then rated. So going a consistent 40mph on flat ground I would likely be more like a ~35% reduction in range going up and down hills vs flat ground.


When I drive longer trips where I’ll have to charge on the road in mountainous areas I count on a 20-25% range reduction. If you are in an area with adiquate access to rapid charging it won’t matter. If you are towing, have external gear (bikes, RTT, rack,…) or have large stretches without charging it will.