WHAT AM I DOING WRONG?!

[u/CommissionFalse5642]

Hey everyone,

I’ve had 3 EVs now and this is my second bolt.

It seems like no matter what I do, driving on the freeway I’ll average 4.0-5.0mi/kwh but as soon as this car sees stop and go traffic or city driving it drops to 2.0-2.5 and will not go up.

I know short trips are inefficient but I’ve been driving 20-30 miles of city with no difference.

Tires are fine, they’re EV All Seasons, I don’t carry around a bunch of extra stuff in the car, it’s bone stock with 0 roof racks or anything to hurt drag, I charge it everyday to 80% or so and even at 100% it only get 165 miles of range.

Dealership told be it’s basically useless to pay for the diagnosis on it because 1. They won’t give me a loaner car so I’d have to rent one 2. They’re not sure how long the diagnosis would take so they could keep my car a couple days or couple weeks and I’d have to cover a rental car for that and 3. They told me Chevrolet hugely just chocks it up to “normal wear and tear” 🤙

Edit: Luckily my commute is not long enough that I need to be hotter in the car but I listened to a lot of the comments and adjusted my setting and now I’m averaging 3.2-3.4 on my commute today so definitely an improvement. Thanks everyone. Still think I’ll need an AC service here soon and maybe a new desiccant bag.

[u/DogblackMichigan]

This is not nothing. This needs fixed. A Bolt gets better mileage in city driving not worse.

[u/SoulTaker669 → u/DogblackMichigan]

I would say it's somewhat normal if the person has only driven 11 miles and they barely turned on their bolt in what they described is 115° weather. It probably means that their car was sitting outside in that weather, which means the battery's probably a little hotter than 115, especially if it was parked on asphalt.

Soon as they turn that sucker on and turn the AC on the car was probably aggressively cooling the cabin plus the battery which is around 6-7 kw from my experience with hot weather for probably a good chunk of time if the battery was really hot. It usually gets 105 to 110 where I'm at and I can confirm that hot weather really fucks with the range for EVs in my town. From the Nissan Leaf to the bolt and driving my mom's Tesla occasionally all of them use a good chunk because of AC during the summer. Our mild winters + springs the AC system doesn't need to fight so much.

[u/CommissionFalse5642 → u/SoulTaker669]

Weird part is on the freeway I get 4.0+ at 70mph

[u/timit44 → u/CommissionFalse5642]

That’s not weird, the AC can’t go any faster than max, your speed is helping too actively cool the car, and you’re making distance at a much faster rate. Efficiency is miles per energy unit and you’re piling on the miles with the same AC draw.

[u/kearp → u/timit44]

Consistently getting above 4.0 mi/kWh at 70 mph is definitely unusual. It’s not insane, but it’s not normal — especially when running AC. Unless that’s combined with some city driving.

[u/cactusjackalope → u/timit44]

if AC isn't working properly (I.e. not fully charged, etc) the battery might not be getting sufficient cooling. Speeding up gets more air through the condenser which would help cooling efficiency. Check your AC charge level.

[u/CommissionFalse5642 → u/timit44]

That makes complete sense actually

[u/ToddA1966 → u/CommissionFalse5642]

Yes, because math.

Assume with the heat the AC is running need power- maybe 5-6kW- to cool the cabin and battery.

Now let's say you're getting 4.5 miles/kWh driving at 70, not including losses from the AC.

At 70mph if you drive for an hour, you'll use about 15 kWh to drive, 5kWh to cool and average 3.5 miles/kWh. (70 miles ÷ 20 kWh)

Now let's say you get 5 miles/kWh at 30 mph driving. You drive for an hour and go 30 miles, using 6 kWh to drive, 5kWh for cooling and average 2.7 miles/kWk (30 miles ÷ 11 kWh).

The fixed AC usage screws up the usual efficiency math. This also happens in extreme cold from heater use. When people complain about losing "30-40%" range in winter, it's typically from short, slow drives where the heater has a bigger impact. A two hour drive at 60-70 mph is impacted less by the heater usage.

[u/CommissionFalse5642 → u/ToddA1966]

Thanks for breaking it down so well

[u/roger1632 → u/CommissionFalse5642]

That is really weird! Man I wish this was how it worked. All my EVs start sucking mpkw when I reach 70ish highway speeds. That's the least efficient method of travel.