Model X efficiency when drafting a Model S

[SSonnentag]

My wife and I had a rare opportunity yesterday. Circumstances required us to both make the exact same drive with both vehicles. I drive the S and my wife drives the X.

I set the cruise/EAP to 70 mph and she set her cruise/EAP to 70 mph with the following distance on level 4. The X seems to want to do 1 mph faster than the S when set at the same speed, so this worked out well.

The X used 52.56 kWh compared to the S with 52.33 kWh.

I don't know if the slight difference in miles is due to speedometer differences or TeslaFi GPS differences. In any case, we drove the same exact distance give or take a few hundred feet. The 5-minute time difference is me sitting in my S waiting for my wife to finish up in a gas station convenience store and related facilities.

Bottom line, the X is more or less just as energy efficient as an S, as long as you're following another vehicle.

 

[jboy210]

Interesting results. You should repeat it when following a semi.

But, If your really want to draft you need to be much closer that that. One or two car lengths. Did that with my brother from LA to Fresno and saved a ton of gas.

 

[Ruffles]

Thanks. I'd love to see the result not drafting anyone...or at least following at a greater distance. I'm always nervous about getting a rock in the windshield so I never follow close enough to consider it a draft.

 

[lowtek]

Next up ... battery efficiency while having your Model X towed to its destination!

 

[jboy210]

Next up ... battery efficiency while having your Model X towed to its destination!

On roads that are downhill both ways.

 

[SSonnentag]

Thanks. I'd love to see the result not drafting anyone...or at least following at a greater distance. I'm always nervous about getting a rock in the windshield so I never follow close enough to consider it a draft.

This is as close as I can find on my TeslaFi account.

About 5.82 kWh (11%) more.

 

[mjptech]

This is as close as I can find on my TeslaFi account.

About 5.82 kWh (11%) more.

View attachment 502897

It's really close, even with that ~25F temperature difference...

 

[scottf200]

Bottom line, the X is more or less just as energy efficient as an S, as long as you're following another vehicle.

That was an excellent comparison and data provided from TeslaFI. thanks.

Interesting results. You should repeat it when following a semi.
But, If your really want to draft you need to be much closer that that. One or two car lengths. Did that with my brother from LA to Fresno and saved a ton of gas.

Definitely do not need to do unit setting of 1 or 2 (they are not car length but time based units, BTW).

Below red boxed Wh/mi in my P90D X over 500 miles not following anyone for any regular time.
Below yellow boxed Wh/mi in my P90D X coming back but following a U-Haul truck at 7 Tesla following units. *Seven* ! 500 miles is a long test and the elevation wasn't the factor.

As well there have been a few occasions where I drafted a semi-truck at 7 units and had my energy graph up where I could see the before and after Wh/mi in a 30 mile time frame (ie. 15bef/15aft). The Wh/mi is remarkable for 7 units. Yes, we all watched the Myth Busters episode where they had to measure liquid

 

[jboy210]

Definitely do not need to do unit setting of 1 or 2 (they are not car length but time based units, BTW).

Not talking about Tesla unit settings. 1-2 car lengths, 20-25 feet behind. Both cars were ICE rice rockets. Tight drafting like in road track or bicycle racing. Oh, to be young and stupid again!

 

[BenderTmoc]

Yes, we all watched the Myth Busters episode where they had to measure liquid

You lost me there but I'm definitely curious, can you elaborate?

 

[scottf200]

You lost me there but I'm definitely curious, can you elaborate?

I am sorry for my terseness and subtle joke. I meant that in such short testing they were doing they were measuring the gas and it was not very much so they could have been off.
I think our measuring is more precise (ie. Wh/mi).

 

[BenderTmoc]

Ooof. I should have thought of that myself. Liquid => gas. Duh. Thanks anyway for spelling it out...

 

[blitzpa]

The aerodynamics of the X are impressive for its size. I'll draft behind semi's when it's reasonable to do so and notice a slight efficiency boost. Imagine if they had kept the no side-view mirror design!