Car Tech 101: Making diesels clean
[MUSIC]
For ages, derided as slow and more noticeably, filthy, automotive diesel engines went in for a big makeover over the last couple of decades.
Common rail injection is a form of fuel injection that can spritz diesel into the cylinders at very high PSI in very precisely controlled bursts.
That kind of control of the amount of fuel, and how often it sprays into the cylinder, combined with turbo charging Revolutionized both the power output and CO2 emissions coming out of diesel engines starting in the late 90s.
Around 2006, ultra-low sulphur diesel fuel became the norm in the UK, Europe and US.
It reduced the dirty sulphur content in diesel fuel from 500 parts per million to 15.
Taking that out reduces the energy content in to the gallon of fuel slightly.
But primarily sets the stage for a key pair of cleaning technologies to kick in.
Selective Catalytic Reduction puts a special catalytic converter in a diesel car's exhaust system.
System.
Inside that can is sprayed a mist of urea fluid that combines with heat and the special metal surfaces in the catalytic converter for a reaction that scrubs diesel emissions way down in several key areas.
The down side of SCR is that you have to add this expensive plumbing to the car's underside and refill the car's supply of urea fluid from time to time.
Typically at 10 to 15,000 mile intervals.
Some dealers will do it for you as a courtesy during routine service, or you could do it yourself with a bottle of the stuff from Amazon or an auto parts store.
It's like adding washer fluid, but it's one more thing to fiddle with.
[MUSIC]
The TDI from Volkswagen.
Right about now, we should have smelled something fishy.
VW was meeting stringent, new US diesel emissions standards from 2009 on.
Without SCR on most of its diesels, which seemed like a trick no other car maker could pull off.
As we now know, they weren't pulling it off either.
These events are deeply troubling.
Retrofitting one of these bulky complex SCR exhaust systems and urea tank
To the effect that TDI VWs and Audis out there is one way VW may have to address the current cars that are on the road and violating emissions standards.
But what if diesel exhaust could be cleaned up before it's even exhaust?
That's what they're working on at the Oak Ridge National Labs where they're developing diesel engine tech that injects fuel into the cylinder early in the combustion cycle.
Something which almost defies the definition of a diesel.
That along with a new breed of sensors demands the fuel timing precisely based on nuanced real time measurement of cylinder pressure could be a big breakthrough.
The diesel engine is, by its nature, a dirty beast, but its fuel flexibility, lovely torque, and high MPG keep it an important player in combustion auto engine.
Even if keeping it there requires a constant stream of new cleaning tech.
[MUSIC]
More car tech, demystified, right now, at CNETOnCars.com.
Click on CarTech 101.
[MUSIC]
[BLANK_AUDIO]
Up Next
Crash Testing New Electric Cars Proves They're Typically Safer
Up Next
Crash Testing New Electric Cars Proves They're Typically Safer
See What Makes the Best Tire for Your Electric Car
See What Makes the Best Tire for Your Electric Car
Why Are So Many Electric Cars, Scooters and Bikes Burning?
Why Are So Many Electric Cars, Scooters and Bikes Burning?
Seen the New 2023 Prius? Here's Why It's Turning Heads
Seen the New 2023 Prius? Here's Why It's Turning Heads
The Bestselling EVs of 2022
The Bestselling EVs of 2022
Best Dash Cams: A Buying Guide
Best Dash Cams: A Buying Guide
GM's Electric Pickups Head On: Comparing the Sierra EV to the Silverado EV
GM's Electric Pickups Head On: Comparing the Sierra EV to the Silverado EV
Meet a Mind-Bending Hybrid: The Sono Sion Solar-Grid EV
Meet a Mind-Bending Hybrid: The Sono Sion Solar-Grid EV
These Are the Cars That Qualify Now for the New Tax Credit
These Are the Cars That Qualify Now for the New Tax Credit
Don't Buy an EV Until You See the Most Important Ones Coming in 2023
Don't Buy an EV Until You See the Most Important Ones Coming in 2023
Tech Shows
Latest News All latest news
The Missing Piece to Apple's Eco-Friendly Mission
The Missing Piece to Apple's Eco-Friendly Mission
First Drive in the All-Electric 2024 Fiat 500e
First Drive in the All-Electric 2024 Fiat 500e
Laptop Buying Guide: What to Look For
Laptop Buying Guide: What to Look For
Boston Dynamics Retires Its HD Atlas Robot
Boston Dynamics Retires Its HD Atlas Robot
Taste-Testing 6 Apple Cider Vinegar Drinks
Taste-Testing 6 Apple Cider Vinegar Drinks
Testing BruMate's Leakproof Tumbler
Testing BruMate's Leakproof Tumbler
Most Popular All most popular
First Look at TSA's Self-Screening Tech (in VR!)
First Look at TSA's Self-Screening Tech (in VR!)
Samsung Galaxy S24 Ultra Review: More AI at a Higher Cost
Samsung Galaxy S24 Ultra Review: More AI at a Higher Cost
'Circle to Search' Lets Users Google From Any Screen
'Circle to Search' Lets Users Google From Any Screen
Asus Put Two 14-inch OLEDs in a Laptop, Unleashes First OLED ROG Gaming Laptop
Asus Put Two 14-inch OLEDs in a Laptop, Unleashes First OLED ROG Gaming Laptop
Samsung Galaxy Ring: First Impressions
Samsung Galaxy Ring: First Impressions
Best of Show: The Coolest Gadgets of CES 2024
Best of Show: The Coolest Gadgets of CES 2024
Latest Products All latest products
2025 Audi Q6, SQ6 E-Tron: Audi's Newest EV Is Its Most Compelling
2025 Audi Q6, SQ6 E-Tron: Audi's Newest EV Is Its Most Compelling
Hands-On with Ford's Free Tesla Charging Adapter
Hands-On with Ford's Free Tesla Charging Adapter
Nuro R3 is an Adorable Self-Driving Snack Bar
Nuro R3 is an Adorable Self-Driving Snack Bar
First Look: The $349 Nothing Phone 2A Aims to Brighten Your Day
First Look: The $349 Nothing Phone 2A Aims to Brighten Your Day
Best of MWC 2024: Bendable Screens, AI Wearables and More
Best of MWC 2024: Bendable Screens, AI Wearables and More
This Concept Laptop from Lenovo Has a Transparent Display
This Concept Laptop from Lenovo Has a Transparent Display
Latest How To All how to videos
Tips and Tricks for the AirPods Pro 2
Tips and Tricks for the AirPods Pro 2
How to Watch the Solar Eclipse Safely From Your Phone
How to Watch the Solar Eclipse Safely From Your Phone
Windows 11 Tips and Hidden Features
Windows 11 Tips and Hidden Features
Vision Pro App Walkthrough -- VisionOS 1.0.3
Vision Pro App Walkthrough -- VisionOS 1.0.3
Tips and Tricks for the Galaxy S24 Ultra
Tips and Tricks for the Galaxy S24 Ultra
TikTok Is Now on the Apple Vision Pro