Hacker News Reader

Comment by bdcravens | Hacker News Reader

Most important point is comparing it to loss of efficiency in gas cars. There's a lot more variance there, given the work that a gas engine done and all the ways it can be maintained (and lack thereof), but most numbers I've seen point to around 10-15% after 100k miles.

View on HN

I track gas added to all of our cars (because my dad and his dad did). I’ve driven several of them to over 130k miles and one to 242k miles. I’ve never seen even a 5% degradation in mileage from wear. (I did see the ~3% drop in mileage when ethanol was added to the standard gasoline mix. I wonder if someone is confusing that for wear.)

If I had a 10% loss in fuel economy, I’d be looking for something wrong and fixing it.

I can second this, and do the same math and tracking (someday maybe cars will reliably do this themselves). The same can be done for electrics (power paid for and delivered to the car versus the miles driven).

There's a lot of this incorrect info floating around in the EV community. I recall one person, a year ago I think, trying to claim that gas cars won't start in the cold.

Not -50F either. 10F and such.

Diesel cars don't run very well in the cold. They still work though unless it's super cold.

Diesel cars work perfectly in the cold. Once an engine has warmed up (half a minute), then it's the same for the car as if it was 30C outside.

Similarly I've been told my EV won't last a day when the winter comes. I live in Houston lol.

I really don't consider myself part of any "EV community"; I'm an EV owner who has owned/bought several gas cars prior (most bought new, so I saw the efficiency drop over time). That said, most of my cars were of the highly efficient variety, Honda Civics and the like, so it may be more evident than in trucks etc.

The common retort I suppose is that if my efficiency went from 38mpg to 33mpg that I must be doing it wrong, similar to how a discussion on location of chargers devolves into a highway driving being an endurance sport, where everyone gets 600 miles of range, fueling up their cars in 3 minutes, with no need for any form of urination.

Gas cars do have trouble starting at cold temperatures though? Ironically it's often due to the starter battery.

Gas cars have absolutely zero issues starting in the cold, unless the battery is not good enough, or the car has another mechanical issue. EG, the car is broken.

To say it's because of the cold, is like saying they have trouble driving on flat tires too.

As a Canadian, who's been driving cars down to -45C mornings for decades, they just start. Older cars, and I don't mean "cars that have aged" but instead "cars from the 60s or 70s" sometimes needed a "block heater", which was basically just a fat resister you'd plug into AC. It kept the engine block warmer.

However I must reiterate... that's not commonly required any more. Not for 50 years.

When I was a kid ('70s/'80s) a car engine might die due to cylinder wear, burning oil and losing compression. I wonder if those might have been noticeably inefficient (say one cylinder of eight still ingesting fuel but not compressing fully and leaking exhaust products into the crankcase). Now I have an EV (fairly new) and an ICE car w/ 220k miles. The ICE car is leaking oil and needs some suspension work but I think it's efficiency is pretty much the same as it has always been.

I rebuilt the engine in my 1961 truck 3 years ago, the bores were worn enough it was noticeably down on power. I can't easily track MPG in it for a precise number (no working odometer), but the mileage increase was significant enough to notice a difference at the gas pump, I'd estimate a 4-5mpg improvement. This would be an extreme case though, I really don't know how that engine even still had enough compression to start. The ring end-gap was slightly over 1/8" (0.128"), spec is 0.016", so on the extreme end of engine wear.

To get back to EVs though, I'm not really sure they will last any longer than current ICE cars. Engine reliability has gotten good enough that a worn engine normally isn't the reason a car gets taken off the road. IME the main killer is either body rust or just too many small parts being worn out to where it isn't cost effective to keep repairing. Suspension parts will wear faster on an EV, since they're heavier than equivalent size ICE cars. I've driven a lot of mechanic specials over the years, and of the 7 cars I've sold to salvage yards only 2 were due to engine issues, the rest were either body rust making them unsafe or just too many things wearing out.

> If I had a 10% loss in fuel economy, I’d be looking for something wrong and fixing it.

Have you never had a car start burning oil due to gasket failures and what not?

All of the cars I've owned had 80k plus miles on them when I bought them, and most recently I disposed of a 2001 Corolla with 265k miles on it. They all had various moving parts that failed at least annually and prevented me from using the vehicle *at all*. I'll take a slightly reduced range on my EV over that, any day.

I’ve had cars that burn/use oil. That doesn’t significantly change fuel economy though.

The kind of person that pays that level of attention is certainly on the far end of the bell curve, as is the person who guns their engine everywhere they go and goes 12,000 miles between oil changes and tire rotations.

15% efficiency loss doesn't sound that major. My car's currently averaging 7.9 l/100km. It it goes up to 9.0 l/100 km, it means that I need to buy an additional 5.5 litres of petrol over 500 km driven, which is around 10€.

I won't happen. Gas cars don't lose efficiency like that, so don't concern yourself.

It's not really a comparable concern in gas cars, though. Range matters a lot more in EV because the charging stations are much rarer than gas stations.

If you lose 15% range in a gas car, ok, you have to get off one exit earlier to refuel. No big deal. But if you lose 15% range in a electric car, that is sometimes the difference between being able to make it to the next charging station (especially DC fast charging) station or being stranded by the side of the highway and needing a specialty tow.

Citation needed. EV chargers are actually pretty common, at least in the UK. Jump in any EV and the satnav will show you all the chargers nearby and they're basically everywhere. Sure perhaps 7kw and not 150kw+ but even grocery stores have many of those 150+ now, even if they don't have their own petrol station.

Yes, I'm sure it depends on the locale. Sorry for not specifying. In the US, particularly more rural areas, it's difficult because we have such vast distances. On a long trip, there aren't enough DC fast charger OR level 2 chargers, the ones that are there are often broken and/or in use, and it is quite the adventure to plot a longer trip.

> Range matters a lot more in EV because the charging stations are much rarer than gas stations.

The classic topic in every EV "debate." Gas car drivers can't imagine having the equivalent of a 7 gallon tank. EV drivers can't imagine having a tank that isn't full every morning when you wake up.

It's not about whether it's full, but whether you can successfully make it to a faraway destination in a reasonable amount of time (& not adding hours & days to the trip).

It's not really a "debate", just a consideration. We recently got an EV, and generally love it, but long trips are more difficult. We ended up taking the gas car because the EV would've added 5-6 hours to the trip, due to a lack of fast chargers along the routes we needed to take and the 200-ish mile range of our car.

For around town, it's wonderful though.

My current EV is comparable to my last gas car in terms of range - about 300 miles (Kia EV6) vs 270 miles (Toyota C-HR) (I'm talking the miles I saw in my use, not the spec sheet)

In Norway, gas stations are now a lot rarer than fast charging stations. That was a fast transition. Some remove pumps to add chargers instead, some just close down.

It's more a matter of your most common use. The average person drives around 40 miles a day. For those in that circumstance, who live in a home where they can charge in the garage, they may never touch a DC charger for months at a time.

Interestingly enough, the lack of fast chargers actually minimizes the issue of efficiency loss, rather than exacerbate it. I drove my EV from Texas to California and back in 2022. It wasn't super convenient, but doable, based on the spacing of fast chargers on the freeway. I had to charge each time I came by one, due to the spacing of them (being every 100 miles or so, I may not be able to skip one confidently). In that situation, a 15% loss in efficiency wouldn't make a difference either way.

I'm curious about battery replacement (1.5%) compared to the rate of engine replacement for ICE vehicles.

My 200k+ kilometers diesel Fiat Punto is as efficient as new.

Reply on news.ycombinator.com