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Comment by boomboomsubban | Hacker News Reader

Is it? The thing's huge, air conditioning is never cheap. A quick search says average cars consume ~25% more gas with AC, making it somewhat high.

I think short trips at low speeds are also terrible for AC, dunno how they did the projections.

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A quick search says average cars consume ~25% more gas with AC, making it somewhat high.

Tons of websites say this but in my own testing during my commute the difference is almost unnoticeable, let alone a full 25%.

my car consumes 5% more with AC on. it's a 2002 Mazda. So, I don't believe 25% number.

I feel the same way. I've never had a vehicle that consumed more than 5% extra with A/C. With my current diesel I can't notice a difference at all.

My source was a government site, make of it what you will. I may have worded it more strongly than I should have. https://www.fueleconomy.gov/feg/hotweather.shtml

Consumer Reports did a study on this and it only reduced gas mileage by 3% on a Honda.

https://shop.advanceautoparts.com/r/advice/car-maintenance/c...

At 65mph and ~85 degrees. The page I linked sources several studies testing at many other temperatures and speeds.

No car takes a 25% hit from the A/C in gas mileage.

>The internal combustion engine (ICE) variant has an estimated fuel efficiency of 14.7 mpg‑US (16.0 L/100 km), decreasing to 8.6 mpg‑US (27 L/100 km) when the air conditioning is on.

It may be a “worst case, only when actively cooling at maximum power” figure. In reality you’d expect ambient conditions to make a big difference to aircon energy use.

No. Sorry the quick search result was dead wrong.

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