Gravity 75 mph Range

[BS8899]

Based on OOS? Again, I don’t think there’s a real control in those tests. Tons of variables. I’d be more interested to understand what Air owners actually are getting. I highly doubt it is 4.3. But again, I don’t know. I, too, am not a sedan person so didn’t follow the Air. I did drive an AGT loaner for a bit and came nowhere close to 4.3. Not even in the 4’s over a 10 day period. If I remember, it was around 3.5 or so.

• I drive between my homes in Phoenix AZ and CA (Ranch Palos Verdes through 2023, exactly 400 miles door-to-door, and Sausalito now, ~780 miles).
• I have a 2022 AGT. Over the years, I drove these trips on 4 different cars; a 2017 Lexus RX450, 2019 Hona Clarity, 2022 AGT, and 2023 Rivian R1S (large pack).
• in terms of "Time Efficiency" (i.e., how long does it take to go from one place to the other), my ICE-hybrids can do the 780 mile trip in ~11 hours. My record was 10.5 hours in my Lexus.
• As for the EVs, the AGT takes ~12.5 hours (780 miles) with two charging stops. From 100% SoC to 5% SoC, the most I ever got from my AGT is ~375 miles range. The Rivian takes ~13.5-14 hours, with 3 charging stops, and slower charging than the AGT.
• So, my conclusions:
  • if range/shortest travel time/range anxiety are your key concerns, go with an ICE hybrid.
  • the AGT is a 375 mile range car when driven 75mph in AZ Hwy and 70mph on CA highways, ~73% of Lucid's advertised range. That said, my drives (I-10/I-5) do have some elevation changes and I am going from 100% to 5%. Hence, if you take all of these into account, I'd say the AGT delivers ~78+/-% of its claimed range (100% SoC to 0%). Still a good range, but not as good as Lucid suggests.
  • My Rivian delivers close to 2.5 mi/kWh, pretty much inline with Rivian's claims.
• To all my CA friends, you folks have no idea what range-anxiety is. There are so many chargers along CA highways you will never get stuck! All you are moaning about is whether you can get to Tahoe from the Bay Area in one charge!
  

 

[Bdr100]

Play with any variables you want, and every range/speed chart ends up looking pretty much like this one:

View attachment 33802

At higher speeds, aerodynamic drag tops every other factor in terms of reducing range. And it's a range killer any way you cut it on a road trip.

The same thing happens with ICE vehicles. You just don't care as much because there is a gas station at almost every exit.

The slope on your graph is a bit extreme. We already know that 70mph range is in the mid 350 miles, so range numbers on left side need significant adjustment.

 

[Bus Driver]

The Air is the most efficient large sedan. The Touring would likely be close to the RWD Model 3.
View attachment 33801
It's interesting that the Model X is only 10% less efficient in OoS 70mph range test than the Model S. The problem with these tests is that wind and weather can make big difference.

Wait, I can achieve 4.0 in my 2022-build GT on 19s?! I don’t think I’ve ever seen that in three years and 66,000 miles of driving. Maybe once, I got over 4.0. But that was coming down a mountain.

 

[hmp10]

The slope on your graph is a bit extreme. We already know that 70mph range is in the mid 350 miles, so range numbers on left side need significant adjustment.

This is not a chart based on Lucid data. It's a chart I pulled off a Google search and is very similar to the slopes seen across charts of multiple EV brands.

I don't see what's so extreme about the slope. Aerodynamic drag increases exponentially with speed.

 

[hyzerfool]

• My Rivian delivers close to 2.5 mi/kWh, pretty much inline with Rivian's claims.

What tires did you have on the R1S? I have the same model and get closer to 2.0 mi/kWh going similar speeds unless I put it in conserve mode.

 

[BS8899]

What tires did you have on the R1S? I have the same model and get closer to 2.0 mi/kWh going similar speeds unless I put it in conserve mode.

I don't remember the tire size off the top of my head. I will look when I get back to AZ in early Dec.

I drive these long trips in Conserve Mode. I have a large pack and quad (Bosch) motors. Conserve mode buys 7 to 9 percent.

 

[Elfin]

The same thing happens with ICE vehicles. You just don't care as much because there is a gas station at almost every exit.

Though not quite as bad because the engine itself gets more efficient at higher loads.

 

[dbsb3233]

Play with any variables you want, and every range/speed chart ends up looking pretty much like this one:

View attachment 33802

At higher speeds, aerodynamic drag tops every other factor in terms of reducing range. And it's a range killer any way you cut it on a road trip.

The same thing happens with ICE vehicles. You just don't care as much because there is a gas station at almost every exit.

As a general profile, yes. The question is the magnitude for each specific EV model and trim, which varies. But the general pattern applies to all EVs, with some having steeper curves and others having flatter curves than that.

 

[Ron_Burgundy]

What tires did you have on the R1S? I have the same model and get closer to 2.0 mi/kWh going similar speeds unless I put it in conserve mode.

I have to jump on this and agree. I am lucky to get 2.25 on my R1S G1 QM. I can get 2.7 if I am going downhill for a longtime and that’s as high as I can get with the A/S tires and aero covers.

 

[TahoeMichael]

Ok. So if range is the priority, one of those should be one’s choice. The IQ supposedly has awful driving dynamics, for example. It also has a massive battery so it’s inefficient to get the range. No idea about the MB, but have read driving is “uninspired” in MB EV.

For me, and I think many folks here, Gravity is the best mix of range, driving dynamics and tech (when it works, I know about bugs…).

The OOS 10% challenge comes to mind when the IQ is discussed. It does have long range, but it achieves that with a huge battery, and so recharging is a real problem.

 

[dbsb3233]

Though not quite as bad because the engine itself gets more efficient at higher loads.

Yeah, it's a different profile for ICE. In fact up to about 55 MPH, ICE is the opposite of EV (ICE tends to get better mileage on the highway than the city, while it's the reverse for EVs). But above roughly 55 MPH it turns south for ICE too.

 

[Elfin]

The OOS 10% challenge comes to mind when the IQ is discussed. It does have long range, but it achieves that with a huge battery, and so recharging is a real problem.

It does have a major problem that charging performance is reduced when HVAC is running (which is what OOS does in their 10% challenge.) Supposedly they've improved this in an OTA update. Without HVAC running it does add energy faster than the Gravity but probably not enough to offset the lower efficiency.

 

[hyzerfool]

I don't remember the tire size off the top of my head. I will look when I get back to AZ in early Dec.

I think I'm more curious tire-wise, are they sort of normal all season? As in, no magic special low rolling resistance hover a little bit off the ground sort of tires?

It could also be that I pile so many snacks and drinks in when I drive that it weighs things down

 

[BS8899]

I think I'm more curious tire-wise, are they sort of normal all season? As in, no magic special low rolling resistance hover a little bit off the ground sort of tires?

It could also be that I pile so many snacks and drinks in when I drive that it weighs things down

I believe they are all season. On these long trips, I drive in CONSERVE mode, I stick to the speed limit, I use cruise control, and I usually drive at nights. All these small things add up to maximize efficiency.

 

[TahoeMichael]

That actually works well for me (the elevation part) since Kyle just lives 30 miles north of me.

But yeah, I've seen conflicting info on how much impact the thinner air really has. I've seen some reports that it's significant, others that it's insignificant.

Air density is a linear component of the drag equation, and air at 5000' is roughly 88% of the density at sea level, so the energy expenditure to overcome drag is about 88% of what it would be a sea level. The challenge is that overcoming drag is only one source of resistance to a car moving, and so it's hard to know the total impact of reduced drag on overall efficiency. Drag goes up with the square of velocity, so at high speeds the altitude reduction of drag will be a significant energy savings. A reasonable rule of thumb is that overcoming air resistance at sea level becomes half the energy consumption of a Gravity at 45 mph.

 

[dbsb3233]

Air density is a linear component of the drag equation, and air at 5000' is roughly 88% of the density at sea level, so the energy expenditure to overcome drag is about 88% of what it would be a sea level. The challenge is that overcoming drag is only one source of resistance to a car moving, and so it's hard to know the total impact of reduced drag on overall efficiency. Drag goes up with the square of velocity, so at high speeds the altitude reduction of drag will be a significant energy savings. A reasonable rule of thumb is that overcoming air resistance at sea level becomes half the energy consumption of a Gravity at 45 mph.

But as you say, it's hard to know how much that impact has vs other impact like rolling resistance of the tires, etc. No doubt there's *some* impact, but there's a lot of conflicting data on how much.

Personally, I never really noticed much difference at higher vs lower altitude in roughly 70,000 miles of road trips the last 5 years. We drive Denver-Vegas about 6-7 times a year, often adding extensions and alternative routes thru WY or NM/AZ. Lots of that is 4000'+ (peaking at 11,000'). But we've also done EV trips through 40 states from coast to coast. There's always different variables, of course, so it's never a perfect apples-to-apples comparison from one drive to another. But I do keep a pretty close eye on efficiency/range and I've never really found high/low altitude to have a significant impact. But that's just personal observation through lots of miles and trips.

Elevation gain/loss is huge, of course, but that's from climb and descent.

 

[borski]

The EQS SUV and the Rivian R1S Dual Max have slightly more range (in thinner Colorado air, really need them all side by side.) The Escalade IQ has much more range.

The EQS I have no idea, but the Rivian definitely doesn’t. The Escalade has twice the battery, so have fun charging it, but yes, technically more range.

Seems roughly the same as Gravity.

 

[Elfin]

The EQS I have no idea, but the Rivian definitely doesn’t. The Escalade has twice the battery, so have fun charging it, but yes, technically more range.

That 341mi result was at 95 percent charge (who tests like that???) They also say the "average speed" was 70mph which is always going to be less efficient than actually going 70mph.
In their most recent test Out of Spec got 376mi to dead. I'm just going by current available test results, on paper the Gravity should have more range at 70mph.

 

[BS8899]

But as you say, it's hard to know how much that impact has vs other impact like rolling resistance of the tires, etc. No doubt there's *some* impact, but there's a lot of conflicting data on how much.

Personally, I never really noticed much difference at higher vs lower altitude in roughly 70,000 miles of road trips the last 5 years. We drive Denver-Vegas about 6-7 times a year, often adding extensions and alternative routes thru WY or NM/AZ. Lots of that is 4000'+ (peaking at 11,000'). But we've also done EV trips through 40 states from coast to coast. There's always different variables, of course, so it's never a perfect apples-to-apples comparison from one drive to another. But I do keep a pretty close eye on efficiency/range and I've never really found high/low altitude to have a significant impact. But that's just personal observation through lots of miles and trips.

Elevation gain/loss is huge, of course, but that's from climb and descent.

Elevation can be a significant contributor when you talk about 5,000ft (Ft Collins/OoS), and Tahoe (6,000ft). This kind of impact can explain a good part of the different between OoS and SoS tests. As another forum reader pointed out, OoS runs the battery completely dead whilst SoC runs it to zero. There might be another couple of percentage differences between the two.

One obvious (though exaggerated) proof-point RE: elevation is why airplanes cruise at 35,000ft-40,000ft. It saves fuel, and the weather is better!

 

[Ron_Burgundy]

Air density is a linear component of the drag equation, and air at 5000' is roughly 88% of the density at sea level, so the energy expenditure to overcome drag is about 88% of what it would be a sea level. The challenge is that overcoming drag is only one source of resistance to a car moving, and so it's hard to know the total impact of reduced drag on overall efficiency. Drag goes up with the square of velocity, so at high speeds the altitude reduction of drag will be a significant energy savings. A reasonable rule of thumb is that overcoming air resistance at sea level becomes half the energy consumption of a Gravity at 45 mph.

Tire friction is greatly reduced by ice in the winter. So ideal efficiency is likely at higher altitudes on ice!