The year is 2024 choosing your next car couldn’t be more confusing. It’s no longer a case of picking a designer badge.
Car buyers like you and me are more demanding than ever! Maybe you want something that’s good for the environment, a bicycle is the best option but you can’t always cycle everywhere can you?
This article is part of a series of articles intended for someone looking to make an informed and well rounded decision, when considering cost, environmental impact and practicality.
Table of Contents
Carbon Dioxide vs Other Pollutants
I want to clarify a common misconception. Carbon dioxide is a green house gas that is bad for the environment.
Carbon dioxide might be bad for the environment but it is not particularly harmful to human health. It does not contribute to local smog, lung disease etc.
Legislated exhaust pollutants are;
- NOx, (Nitrogen Dioxide & Nitrogen Oxide)
- Carbon Monoxide (CO) and
- Hydrocarbons
these are the big three tailpipe pollutants that are considered harmful to human health.
Exhaust pollutants in the US and Europe have strict limits placed on them, if the vehicle exceeds the limit it cannot be sold in that market. There is no limit on carbon dioxide emissions.
A Ferrari might have a very large V12 engine that creates lots of CO2 (because it burns lots of fuel), but thanks to the emissions controls system, namely the catalytic converters, the vehicle is able to keep below the emissions limit.
Are Hybrids ‘Green’
Hybrid vehicles are generally considered to be more environmentally friendly than conventional gasoline-powered vehicles, as they can reduce emissions and improve fuel efficiency. However, the extent to which hybrids are ‘green’ depends on a variety of factors, including the specific type of hybrid vehicle and the energy source used to power it.
Given a choice between a full hybrid and a conventional ICE car, I would say the hybrid is more ‘green’. This is because it will generally consume less fuel to cover the same distance. Read this post I wrote to find out why! Not only that, around town – waiting at traffic lights etc. a hybrid will typically turn off it’s engine, and pull away without the engine.
What is a Dirty Cough
On the flipside, a conventional ICE vehicle is likely to be maintaining a hot catalyst, hot catalysts are very effective at minimising exhaust pollutants. If you want to learn more about this, check out this article I wrote: Discover What 3 Exhaust Gases a Catalytic Converter Cleans When it’s Working
Hybrids engines typically burst into life under much higher driver demand (eg. rapid pull away), this can lead to emissions breaking through the catalyst. Having worked for many years in the aftertreatment industry this was a huge engineering challenge faced by hybrid aftertreatment engineers.
The problem is when the catalyst is cold it is not very efficient at converting harmful pollutants. Catalyst gets it heat from a running engine, so for a vehicle that spends lots of time with the engine off, the catalyst cools down / never warms up. When the engine does fire up, it’s usually a much higher mass flow so most of the dirty NOx, CO etc go straight through the catalyst and into the atmosphere.
One solution is to add more catalysts to the exhaust system. It’s no coincidence that Toyota Prius’ suffer a high rate of catalyst theft, they have a close couple (under the bonnet catalyst) as well as an underfloor (easy to steal) catalyst.
Do Hybrids Need Catalytic Converters
Yes, because hybrids have internal combustion engines they will need a catalytic converter. Any passenger vehicle with an internal combustion engine typically has a catalytic converter to control tailpipe emissions. To learn more about catalytic converters, and what gasses they convert, check out this post I wrote.
Is a Conventional ICE Car More Green
Not really, who are you kidding! Some people argue that maintaining an old ICE is more environmentally friendly than producing a new ‘clean’ vehicle. I don’t really agree with this ideology. Car’s are unfortunately throw away items. They are not designed to last much past 15 years old. Keeping old car’s on the road is not always an option for everybody.
If nothing more, the attitude of avoiding ‘new’ prevents progress – I’m glad we are not all driving around in Morris Minors from the 60’s under the guise of being green!
I’m an engineer and accept that cars are machines designed to do a job, as the years pass, small improvements can be made not only to efficiency but also to safety. Recycling might be good for the environment – it’s not always good for the humans living on the planet though (think NOx reduction and safety systems that save lives).
Does a Hybrid Pay London Congestion Zone
Yes hybrid cars still pay, they are NOT exempt from the London congestion zone charge. Fully electric vehicles are eligible for a discount. Motorcycles however, don’t have to pay, as they don’t really contribute to congestion! For more info on exemptions, see the TfL website for details.
Does a Hybrid Have to Pay for ULEZ
Generally, no, hybrids don’t have to pay for the London Ultra-Low Emissions Zone (ULEZ). Provided your vehicle is euro 4 and above for petrol, or euro 6 and above for diesel, no charge is payable.
Read the section above Carbon Dioxide vs Other Pollutants, ULEZ is nothing to do with ‘gas guzzlers’ or cars with high CO2 output. Provided your vehicle is a Euro 6 or above diesel, or Euro 4 and above petrol then it is considered ULEZ compliant.
London’s ULEZ is intended to improve air quality in the busy city centre of London. Due to the unique way that diesels were promoted 10 years ago, the limits (in Europe) placed on a diesel were far more lenient than the same model year petrol. That’s why a euro 4 petrol from eg. 2005 is considered just as clean as a 2015 euro 6 diesel vehicle!
Some early Toyota Prius hybrids are so old they don’t meet the euro 4 emissions standard, as a result they still must to pay to enter the ultra low emissions zone.
Before You Go…
Are you interested in buying a car that’s green but can’t afford a Tesla? Check out these other posts to help you learn more about vehicle technology from me – an industry insider
