Sulfur/Rotten Egg smell in winter?

LOL. Then it will have no concerns about you, I'm sure.

 

Is there another driver who drives it very gently...then you stomp on it?

 

For USA. EPA has mandated extremely low gaso sulfur several years ago with some phase-in period. EPA does leave room for small oil companies to catch up on a slower pace.

I would assume if you are using gaso from one of the big majors, it must be getting quite low sulfur by now.

Rotten egg smell, assuming your nose is accurate, is H2S (hydrogen sulfide) and would tend to implicate the 12v battery under the Gen4 hood now. Seems unlikely, but recall last year a woman died due to H2S in a Porsche Cayenne apparently due to H2S from the 12v battery under the driver's seat. We've had some reports of smells from the HV battery, but not on Gen4's. I guess you have the NiMH battery.

 

Here's my 2 cents.
I think I noticed this a few times per year with my gen2 and gen3 in wintertime.
It occurred when I started the car in the cold and for some reason left it running for a while (forgot something inside, was packing stuff, scraping the windows etc, so the car was running for a few minutes after cold start).
At some temperature (a little bit after startup) there's a rotten egg smell from the catalytic converter, it goes away after it reaches a higher temperature, so you only get a few puffs of that silent avenger.
(a "silent avenger" is what we call a silent but extremely stinky fart here in my native Finland).

I also recall that when catalytic converters were first introduced (in the 90's I guess) people were always joking about the rotten egg smell.

So IMO that is the catalytic converter struggling with wrong temperature and cold engine.
Never had any trouble whatsoever with those 2 cars during the 8 years I had them, so IMO you have nothing to worry about.

 

1987 it was common - early Cat Converters, plus poor fuel. My Dad's car did it when cold initially, and you often smelled it in traffic, but after a year or so it stopped it, I believe fuel quality improved. I've only smelled it very occasionally since - and I suspect a bad batch of fuel.

 

Yes I remember this being much more common in the olden days.
It might be that the sulfur content is higher here.

I checked.
The fuel I use Neste Futura EN 228 95E10 has a sulfur content between 1,0 to 10 milligrams per kilo in their specs.
So I guess some batches have more/some less.

No idea if that 10 mg/kg is a lot or not.

I bet that also the cat converter on the Prius is far better and reaches operating temp much faster nowdays.

 

Man, it's spooky to have a Neste (Finnish refinery and gas station company) add pop up on this site right after I wrote that.
(Neste literal translation is Liquid so it's the Liquid Company ).

 

Actually the Prius first priority is low pollution, not fuel economy.
That is why the engine warm-up cycle is so long. They try to get the engine where it will run at optimal temperature & speed when needed. That means it warms up as fast as reasonably possible to minimize pollution.

 

"first priority is low pollution, not fuel economy"

Yes. I often make that exact same quote about the Prius to people who ask about the car.

Can't remember where I read/heard it first.

The guys at the Toyota service center here say that exact line too (and that there are no leaks in the car ever; nothing; oil, cooler fluid, breaks, a/c system). It's a remarkable car in that way, even compared to other Toyotas that have a pretty good reputation here too.

It's mainly low pollution not fuel economy.

 

10 mg/kg is ultra low sulfur = 10 ppm Sulfur.
That's about as low sulfur as you can get considering even if the spec were zero, it would be impossible due to just picking sulfur from contamination in pipelines etc.

To put it in perspective, the "old" days (the were no sulfur specs) sulfur was probably as high as 3000 ppm in gasoline, especially in the USA. EU was generally lower I think though, as they did not "crack" as much due to better diesel demand. Similar is true for diesel sulfur now ultra low sulfur. Jet fuel still has the higher sulfur spec 2000 ppm or so.

The purpose of the ultra low sulfur is to enable cat converters and other post-treatment technologies to operate at peak efficiency.

In the USA, smaller companies are sometimes exempted from some of the regulations, so I don't know if it is possible for off-brands to be a little higher sulfur.

 

Smart Sensor Combustible Natural Gas Detector Propane Flammable Sensor Portable Gas Leak Detector with Sound Light Alarm Gas Sniffer High Sensitive - Walmart.com

I would suspect the neighborhood you were driving in, a gauge shouldn't break the bank, and if safety s concerned, safety first.

 

Mine did this today. The temp was about -8F. Strong smell of sulfur inside the car. I had just had the trunk open very briefly though and when I got back in the car it was super strong inside the car. I then drove about 5 miles and got out and could still smell it by the exhaust but it had went away inside the car. It’s a 2018 with about 15500 miles.

 

My car is giving off a strong burning rubber/sulfer/electrical burning smell (can’t narrow down which one exactly) and no lights have come on. It’s overwhelming at this point but mainly on exterior of vehicle. Coming mostly from rear passenger back tire well is where we’ve narrowed it down to. I’ve heard it could be sooooo many things and I’m stressing that something is coming to a slow burning end somewhere in my car. Only owned it two months! 2018 Prius prime. HELP.