[rowyourboat]

Actually, it wouldn't, kerosene and diesel are pretty similar, so it would not be surprising if a diesel car engine can run on SAF.

That being said, it's by no means a given, modern diesel engines are highly optimized and might have trouble with kerosene/SAF, especially given the different lubrication qualitities. Old diesel engines, however, should be fine, they can run on pretty much anything.

[hef19898]

Some Cold War era fighter engines were able to run diesel for a while, tge reasoning was to allow quick re-location of the aircraft to safety. They needed basically a full rebuild if run on diesel for too long.

And all multi-fuel engines the military tried, e.g. in the Chieftain (if memory serves well), were rather underwhelming and ran mostly on diesel anyway.

Old disel engines are fine with all kinds of stuff, modern ones a lot less.

[jabl]

> Some Cold War era fighter engines were able to run diesel for a while, tge reasoning was to allow quick re-location of the aircraft to safety. They needed basically a full rebuild if run on diesel for too long.

Interesting, haven't heard of that. But yes, I can imagine with diesel containing heavier hydrocarbons than kerosene, there could be a buildup of soot deposits on the hot parts of the engine. Might also be some certification issue, that if you operate with out-of-spec fuel then you need to overhaul the engine before it's considered flight worthy again (even if there might be no problem with the engine per se).

Then again, don't these naval ships with gas turbine engines run on something like standard light marine diesel oil?

> And all multi-fuel engines the military tried, e.g. in the Chieftain (if memory serves well), were rather underwhelming and ran mostly on diesel anyway.

The Chieftain engine was designed to be "truly" multi-fuel, being in principle capable of running on both diesel, petrol, and anything in between like kerosene.

If you limit the multi-fuelness to diesel and the current day narrow cut kerosenes that are used as jet fuel, it's a much simpler problem.

E.g. Western military diesel vehicles tend to be specced to run on diesel or JP-8 (the military variant of standard Jet A-1 jet fuel, with a few additives). And aviation diesel engines used in some GA aircraft tend to be certified for Jet A-1 (and they are often modified versions of standard automotive diesel engines).

[bombcar]

The military likes "one fight, one fuel" and so the vehicles are modified to run on Jet A, basically.

There's also the difference between "will it work" and "will it work for continual use".

[dataflow]

Car engines run on diesel? Is this something most people ever encounter?

[londons_explore]

Like half the cars in Europe run on diesel.

It never became popular in the US, although there are still a few cars there that run in diesel.

Diesel engines are typically more reliable and cheaper to run than gasoline. More low-end torque also made them easier to drive with a manual gearbox.

They never became common in the US partly because of differing emissions requirements.

[prmoustache]

Diesels are mostly cheaper to run because european governments artificially reduced the taxing on diesel comparative to gasoline as an help for the economy since most trucks were running diesel for the best low-end torque.

They tend to have a bit better economy but an higher price, so in the end it depends on how long you keep them and the difference is not that positive in countries that tax both fuel the same, like Switzerland.

[davidzweig]

Diesel engines run at higher compression ratios, 20:1 vs. 10:1 IIRC, resulting in higher thermal efficiency, and they also don't need a throttle valve, meaning there is no pumping loss at partial loads. The higher compression ratio also means they must be stronger (heavier and more expensive).

Modern gasoline engines have a few more tricks though and reduce the gap (like very high top gear, direct injection etc.).

[londons_explore]

> no throttle valve, meaning there is no pumping loss at partial loads

I believe this effect is small compared to the alternative, which is that partial loads have dramatically excess air. That excess air isn't involved in the combustion, but still gets heated and pumped through the exhaust. That energy loss exceeds the pumping loss through a throttle on a part loaded engine.

Obviously the ideal case for both engine types is that you run it at a lower RPM whenever you need less power out. Unfortunately, that has other downsides (mostly slower response when you floor-it). Luckily, hybrid electric systems mitigate much of that downside by providing rapid response with electricity and allowing your engine to sit at 1000 rpm and 80% throttle in a super high gear while cruising 70mph on the freeway.

[dontlaugh]

There are actually pumping losses due to things like ERG valves. Modern car diesel engines have very strong engine braking as a result.

[Symbiote]

Just under half, 42.3%. Detailed statistics: https://www.acea.auto/files/report-vehicles-in-use-europe-ja...

(I checked as I didn't believe it was half, but I see there's significant variation by country.)

[jug]

It's super common here in Sweden. Hell, we have a diesel car! The used car market was full of diesel cars. All petrol stations here have diesel tanks. It's diesel all the way down!

They need less fuel than petrol, but one issue is that they don't lend themselves well to 100% city driving because this can lead to costly diesel particulate filter repairs as they clog up. Diesel cars automatically regenerate the filters (burn the muck to ash) as you drive e.g. over 40 mph for >25 minutes or so. (depends on car model) You should drive like that at least once a month.

However, where I live, longer distance driving is pretty common.

They're falling out of favor with rising diesel prices since covid and of course EV's. Companies here go full EV nowadays for several reasons, public image only one of them.

I'd also like to go electrical but seems like we're still stuck for yet a few years because they still don't offer charging poles in apartment garages very liberally, and for any kind of convenient EV use, it honestly builds upon the fact that you can charge it overnight close to home.

[mikeyouse]

Yes? Millions and millions of them..

[dataflow]

You're talking cars? Like sedans? Not, like, pickup trucks? Which cars run on diesel?

[glitchcrab]

Why should the type of car matter? It's just an engine, you make it a bit more compact and it will fit in a sedan. Voila, you have a diesel sedan. Sales of diesel sedans have been slowly decreasing in most European countries Inn recent years, but it wasn't that long ago that more than half of all passenger cars (in some countries) were diesel. Of the 4 cars I've owned, 2 were diesel.

[jon_adler]

My car is a BMW 640d from 2016, a sports saloon. Diesel cars are quite popular in Europe.

[almostnormal]

Anything. Even the smart (the small two-seater) was available with a Diesel engine (when those still had combustion engines).

[mikeyouse]

Lol, did you miss the whole "Dieselgate" thing? Something like 30% of car sales in the EU are diesel with options in ~every brand.

https://www.carwow.co.uk/economical-cars/diesel

[dataflow]

I didn't miss the overall scandal, but wasn't aware these were ordinary cars running on diesel (or of the nickname for that matter).

Edit: Actually it's more likely that I just forgot the nickname, but yeah.

[mikeyouse]

Yeah, 11 million diesel vehicles were recalled by VW -- nearly all were ordinary cars (they don't even make a heavy truck). Mercedes, BMW, Audi, VW all sell (or used to sell) diesel cars in the USA. They all certainly do in Europe, where they're joined by all the European brands like Renault and Seat.

Post-scandal, fewer manufacturers are selling them in the US, but there are millions sold every year worldwide in plain old passenger cars.

[Angostura]

My car is diesel (in the UK) it was popular a few years ago because CO2 emissions are reduced. Unfortunately particulate emissions are problematic. Hence modern diesel cars need Ad Blu to help catalyse their destruction.

[alanfranz]

Not common in the US, but quite common in EU, apparently.

Source: I own a diesel car, Kia Cee’d 1.6L

[dataflow]

TIL. Thanks!

[_yb2s]

I've mostly owned European diesel passenger cars (in USA). It's lower maintenance, more efficient, I like the way they drive (more torque/cool sound), and a fun hobby with a great community of hobbyists that help each other out.

It's rare enough that I often get very concerned gas station attendees warning me that I'm "accidentally" putting diesel in my car.

[hypercube33]

Up until the VW scandal GM was pushing diesel in most of their fleet - from the Chevy Cruze, Equinox to the Colorado all had strait 4 diesels as a premium tier option.

[LeoPanthera]

You're probably American. Diesel cars are common in Europe.

[ponector]

Yes, even in the US.

Have you heard about Dieselgate?

[vlabakje90]

16% of personal vehicles in the Netherlands are currently diesel cars. About 20% of all vehicles sold here last year were diesel vehicles. So at least here, it's very common for people to drive a diesel car. They come in all sizes.

[k1t]

In the US, diesel cars are rare, to the point that most gas (petrol) stations offer just a single diesel pump.

But yes "clean diesel" took off on the EU (somewhat) but in the US diesel means dirty smelly trucks/buses

[jabl]

Modern Ultra-Low Sulphur Diesel (ULSD) is the standard road diesel in both the EU and USA since many years now. And with modern common-rail engines with electronically controlled direct injection, you no longer get the big black clouds of soot when you push down the pedal either (unless you're one of those "rolling coal" morons that mod their trucks to intentionally produce more of it). And further, modern diesel cars tend to have particulate filters and urea catalysts etc.

So all in all, a modern diesel is pretty clean. Not as good as a modern gasoline car, but still reasonably ok and massively better than old diesels.

[bombcar]

Many of the car-buying Americans have the idea of "diesel car" from old Mercedes 240Ds and such, which had the acceleration of a dead snail against a headwind on a good day.

There is nothing inherently requiring diesel cars to be slow.