# Forums

## Projected range

Is it true to have a better projected range when using AP?

Bighorn | 17. huhtikuu 2019

Depends how you drive. It's just an efficiency metric.

kevin_rf | 17. huhtikuu 2019

Don't think any hypermilers have actually tested it.

On ICE's you typically lose a few percent with cruise control because it tries to keep you at constant speed. Can't see AP/EAP being any different, manually driving an alert driver should be able to apply and coast on electrons more efficiently.

parmesan | 17. huhtikuu 2019

I have found the AP to be slightly less efficient while driving with heavy traffic..
For e.g.
I slow down when I know the car in front of me is going to slow down or the lane is going to merge. AP cant do that yet.

Carl Thompson | 17. huhtikuu 2019

I tested it and I get about 5-10% better efficiency driving manually than with AP on. Part of the reason I rarely use AP.

Iwantmy3 | 17. huhtikuu 2019

Carl,
I would be surprised if it was that much different. I could see how it might be impacted by heavy traffic (as per parmesan's point) but on the open road it should be similar. I couldn't tell you myself since almost all of my long distance travel has been with EAP on.

LBTed13 | 17. huhtikuu 2019

I have a 27 mile commute (5 miles surface street/22 miles freeway) and I've been using AP in stop and go traffic on the freeway with a 4 car distance. The car slows down and gets within one car space of the stopped car in front before stopping. For about 20-22 of those freeway miles, I'm in a single lane with AP on. It usually calculates the trip using 13% of the battery from start to finish. However, I'd say most of the time it has used 10%, maybe 11% by the time I get home.

Kary993 | 17. huhtikuu 2019

Look at the Kw/H energy graph over 5/15/30 miles...a much more accurate way to measure human against AP efficiency. I have not done this yet but I am sure I can beat AP in efficiency particularly in medium to heavy traffic on a freeway, but in heavy traffic on a freeway AP will never run into a stopped car either ;)

Seth.e.levine | 17. huhtikuu 2019

Unfortunately AP just tracks the car ahead of you and doesn't look ahead to the 2nd or 3rd car ahead of it. It tries to track the car ahead's speed almost exactly and this results in a slight herky jerky motion that reduces efficiency. That said, I use it when traffic is either light or very heavy.

Bighorn | 17. huhtikuu 2019

@seth
The car apparently tracks more than one car ahead because since early on people have reported experiencing emergency braking when the car two ahead stopped short even though they didn’t see it or the car in front ran into it.

beaver | 17. huhtikuu 2019

@Bighorn yes the radar can sometimes see two cars in front, on the 110 in LA my M3 slammed the brakes on before the car in front of me slammed his brakes. He narrowly avoided rear ending the car in front.

Efficiency is highly situational dependent. If you are a chill driver it’s probally worse (one reason is that it uses the brakes more than needed, I.e. brakes faster than regen alone). If you are a heavy foot driver than AP will be more efficient for the same road.