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Rolls-royce confirms all of its current engines can run on 100 percent SAF
- LeoPanthera 3y agoFor those who didn't click: Aviation engines. Not car engines.
- dataflow 3y agoWould be weird for cars to run fine on sustainable aviation fuel!
- rowyourboat 3y agoActually, 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.
- dataflow 3y agoCar engines run on diesel? Is this something most people ever encounter?
- alanfranz 3y agoNot common in the US, but quite common in EU, apparently. Source: I own a diesel car, Kia Cee’d 1.6L
- dataflow 3y agoTIL. Thanks!
- mikeyouse 3y agoYes? Millions and millions of them..
- dataflow 3y agoYou're talking cars? Like sedans? Not, like, pickup trucks? Which cars run on diesel?
- mikeyouse 3y agoLol, 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 https://www.carwow.co.uk/economical-cars/diesel
- dataflow 3y agoI 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 3y agoYeah, 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.
- jon_adler 3y agoMy car is a BMW 640d from 2016, a sports saloon. Diesel cars are quite popular in Europe.
- 3c6bYDXLMj 3y ago[dead]
- vlabakje90 3y ago16% 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 3y agoIn 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 3y agoModern 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 3y agoMany 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.
- londons_explore 3y agoLike 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.
- Symbiote 3y agoJust under half, 42.3%. Detailed statistics: https://www.acea.auto/files/report-vehicles-in-use-europe-january-2021-1.pdf 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.)
- prmoustache 3y agoDiesels 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 3y agoDiesel 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 3y ago> 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.
- ponector 3y agoYes, even in the US. Have you heard about Dieselgate?
- LeoPanthera 3y agoYou're probably American. Diesel cars are common in Europe.
- jug 3y agoIt'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.
- hypercube33 3y agoUp 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.
- Angostura 3y agoMy 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.
- _yb2s 3y agoI'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.
- hef19898 3y agoSome 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 3y ago> 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 3y agoThe 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".
- nvy 3y agoRR doesn't make automobile engines any more; they're BMWs under the hood. RR's aero engines are generally very well-regarded.
- jabl 3y agoFrom wikipedia (https://en.wikipedia.org/wiki/Rolls-Royce_Motor_Cars https://en.wikipedia.org/wiki/Rolls-Royce_Motor_Cars): > Rolls-Royce Motor Cars Limited is a British luxury automobile maker which has operated as a wholly owned subsidiary of BMW AG since 2003 ... > The Rolls-Royce Motor Cars subsidiary of BMW AG has no direct relationship to Rolls-Royce-branded vehicles produced before 2003, other than having briefly supplied components and engines. The Bentley Motors Limited subsidiary of Volkswagen AG is the direct successor to Rolls-Royce Motors and various other predecessor entities that produced Rolls-Royce and Bentley branded cars between the foundation of each company and 2003, when the BMW-controlled entity started producing cars under the Rolls-Royce brand. The "actual" Rolls-Royce company with a lineage going back to the beginning of the brand (https://en.wikipedia.org/wiki/Rolls-Royce_Holdings https://en.wikipedia.org/wiki/Rolls-Royce_Holdings ) has exited the car business, and nowadays makes jet engines, gas turbines, and nuclear reactors.
- pintxo 3y agoThe story of how BMW came to own the name, and VW the company is hilarious and includes a law firm having to pay lots of money to VW.
- piva00 3y agoVW's history with corporate structure and brands is a clusterfuck in general, haha, the ownership structure between Volkswagen AG, Porsche SE and Porsche AG is pretty convoluted, then you add other VW-owned brands: Audi which has Lamborghini, Ducati, and Bentley as subsidiaries, Bentley itself has been owner and subsidiary of Rolls-Royce through its history, ending up owning the brand for cars lately. If anyone has ever seen a timeline diagram of their corporate structure I'd be very interested to see, just to get a sense of how much more of a clusterfuck it is than the tidbits I know about.
- adolph 3y agoDon't forget the Rimac-Bugatti structure: https://www.thedrive.com/tech/41414/rimac-just-bought-bugatti-heres-why-its-a-huge-ev-bet-for-vw https://www.thedrive.com/tech/41414/rimac-just-bought-bugatt... Volkswagen group has been said to have slated the sell-off of Ferdinand Piëch's "favorite toy" since his death in 2019. . . . The complicated corporate ownership structure of Bugatti-Rimac places Rimac Group as the majority stakeholder of the endeavor with 55 percent of the control. Volkswagen-owned Porsche retains the other 45 percent of ownership. Above Rimac Group sits another number of shareholders, beginning with CEO Mate Rimac who controls 37 percent of the company. Porsche controls 24 percent of Rimac Group, Hyundai has 12 percent, and "other investors" amass the remaining 27 percent.
- jabl 3y agoNice, though since the entire point of SAF is to be a drop-in replacement for fossil jet fuel, this news is a bit of a nothingburger. (Of course, since this is aviation, best to test it so you don't end up with the engine(s) conking out up in the air in case the SAF isn't quite the drop-in replacement it's ostensibly supposed to be.)
- notfed 3y ago> ...our commitment to becoming a net-zero company by 2050... So, I'm building a bridge. Should be done in 2050. Any investors interested?
- wiz21c 3y agoIf they want clean aviation, they can just do it. But please, could they make sure they let the customers pay for that through their ticket price ? I don't want my tax money to be used for that.
- kolinko 3y agoThat is what's happening. When you buy a plane ticket, in many airlines, you have an option to pay extra to fly on SAF.
- parski 3y agoWhen you buy your ticket you have an option to donate to the airline's greenwashing campaign.
- RugnirViking 3y agowouldn't be surprised if they were BOTH able to claim subsidies based on this as well, and write it off on their taxes. Triple dipping !
- PlunderBunny 3y agoYour cynicism might be warranted, but it's now always true. The airline I fly for domestic travel (Air New Zealand) has - in the past - donated some of the money from customers selecting to offset emissions, to the Native Forest Restoration Trust [0], a charity that buys strategic parcels of land, re-plants, and then maintains the land after protecting it forever for the public using the QE II trust. I don't consider that to be greenwashing - that's real and useful. 0. https://www.nfrt.org.nz https://www.nfrt.org.nz
- 3y ago
- notfed 3y agoWhat really is sustainable aviation fuel (SAF)? Is it one thing?
- thepangolino 3y ago[dead]
- guidedlight 3y agoAs far as I can tell it’s basically used cooking oil and waste fats.
- darreninthenet 3y agoAnd the planes will smell delicious
- nielsbot 3y agoI have noticed that bio-diesel cars smell like burning french fries... so maybe you're not that far off...
- Ralo 3y agoInteresting. I've been running that for years in my diesel truck. A mechanical diesel will run basically whatever you can pump through its fuel system. I assume jet engines are roughly the same. However they have some major standards, and can't risk running recycled fryer oil from the Chinese restaurant down the street.
- earthscienceman 3y agoWhat truck do you have, how did you modify it, and whats your opinion on why it's not more common?
- Ralo 3y ago1994 Toyota pickup with a Om617 swap. I bought a kit for the engine swap then did all the work to swap it. I did nothing to handle the oil. It just works. You pour it in the tank and go. However, it doesn't work in the winter without a heater or additives. It's not more common because a) mechanic diesels are old technology and means you'll be driving an old vehicle. b) WVO is a hit or miss in your area. Lots of restaurants will get paid for their old oil by recycling centers so most wont give it away. c) processing it is tough until you get a system in place As well you can run on so many different fluids. Waste motor oil, waste transmission fluid, brake fluid, etc.
- devoutsalsa 3y agoIf you've never watched a video on manufacturing jet engines, here's a video! The intersection of bleeding edge materials science and rigorous safety concerns is pretty interesting. Inside Futuristic Factories Building World Largest Jet Engines -- https://youtu.be/yPBLpwXTelI?si=U2Z2J18rAKm6mb8w https://youtu.be/yPBLpwXTelI?si=U2Z2J18rAKm6mb8w
- simonhorlick 3y agoI don't understand how this is sustainable. The fuel is still being combusted and releasing CO2 isn't it?
- rantallion 3y ago> Whereas fossil fuels add to the overall level of CO2 by emitting carbon that had been previously locked away, SAF recycles the CO2 which has been absorbed by the biomass used in the feedstock during the course of its life. Source: https://www.iata.org/en/programs/environment/sustainable-aviation-fuels/ https://www.iata.org/en/programs/environment/sustainable-avi... I guess it's reasonable to claim that it's sustainable if it's part of a cycle rather than just being a source of CO2 dug straight out of the ground. We still have a way to go with carbon capture but this feels like an improvement over the current fuels.
- tonyedgecombe 3y agoIt's greenwashing, they are hoping we won't pay too much attention to air travel as it's clearly impossible to switch the whole fleet to SAF. For the UK we would need to switch half of our agricultural land to growing feedstock in order to switch to SAF. https://eandt.theiet.org/content/articles/2023/02/uk-would-have-to-give-up-half-its-agricultural-land-to-sustain-net-zero-flying-study-finds/ https://eandt.theiet.org/content/articles/2023/02/uk-would-h...
- kolinko 3y agoIt may not scale, but it's not greenwashing - for it to be green washing, you'd need either claims of lower co2 to be false, or pretend that this solves the issue completely. Lufthansa, at least - when I checked - made no such claim. I reviewed their compensaid site thoroughly (afraid it's just greenwashing), and their communication seems very honest.
- parski 3y ago"Net zero by 2050" sounds like greenwashing to me.
- neves 3y agoWhat are the downsides of Aviation SAF? In Brazil we have cars that work with ethanol. Ethanol increases the engine power, but the car has just 70% of autonomy.
- woodruffw 3y agoWhat does autonomy mean in this context? Range?
- ihattendorf 3y agoYeah, "autonomia" (autonomy) is used to describe a cars range in Portuguese where we would normally use "range".
- dkjaudyeqooe 3y agoOnly one: a lack of availability/scale and consequent cost. It's a problem that can be solved.
- buster3000 3y agoethanol fuel, by itself, doesn't increase engine power. Ethanol allows the use of higher compression-ratios/increased ignition-timing/higher air-density than typical petroleum tunes due to lessened chance of detonation.
- verisimi 3y agoMy car has zero autonomy. It's fine.
- verisimi 3y agoWhy not do this for cars, and be done with the electric car nonsense?