[Closed] Car Emissions in the 60/70's

Carburettors.....

So mostly unburnt hydrocarbons.

You can really taste them when you go back in time to parts of Russia and FSU

Lots of lead

Absolutely tons by comparison, I would also guess.

MPG in the 60/70s was pathetic. 30mpg was considered really good. My dad's V8 Ranger Rover did about 12mpg!

Mot Pre 92 limits on emissions

3.50 % co

1200ppm hydrocarbon

Pre 88 4.5 co

From memory..

All you could do is look at the mpg figure and try and work it out

There were less vehicles on the roads then though so although they were probably dirtier, the volume was lower.

Suspect though, the volumes made little difference.

Fuel Consumption – I would have said about the same for small/medium cars

I learned to drive in a D reg Fiesta MkII with a 950cc engine. Not sure on the 0-60 but suffice to say it wasn't quick. Probably 17-18s I'd guess. On top of that it had no safety features, a manual choke, four gears, and the handling was dreadful - it understeered terribly when pushed.. or so I heard *ahem*. For all that lack of engineering, low power and general crapness it did about 35-40mpg on open country roads without traffic. And it was scrapped after about 100k miles because the subframe went rusty.

My current car is now old, but it is much larger, vastly more comfortable and refined, has about 4x more power, is packed with safety features, it's 6 speed auto, 50% higher top speed, probably less than two thirds the 0-60 time, AND is around 50% more economical. It's also on 160k miles, is older, and has no rust.

And people will still try to tell you modern cars are rubbish. Admittedly it was more expensive when new, I'll give you that.

Emissions used to be much higher.

Just look at one, admittedly fairly dark, cultural trope from the 70's and 80's - gassing yourself by running your car in a closed garage.

Doesn't really work these days, you would probably starve to death first.

Factor in limited fuel injection, leaded petrol, higher sulphur fuels and yes cars were much dirtier

What I can’t really compare is emissions. I’ve looked online and can’t find anything related to vehicles from that period. I’m guessing but I’d say they were horrendous.
Anyone have an idea what they were pumping out?

I think you'll find that modern cars are much cleaner on idle, startup, and warm-up. Carburettors can work very well once you get the engine warmed up and are cruising at constant throttle, but they struggle at low revs and when the engine is cold. Given that most urban journeys are fairly short, that makes a huge difference to air quality in cities.

There were less vehicles on the roads then though so although they were probably dirtier, the volume was lower.

This, the most surprising thing about those empty roads during lockdown was that is wasnt "lowest ever traffic levels" but only the lowest since the early 1970s.

The other thing is that testing is done at idle or fast idle, not under load. Fuel injection will remain pretty much stochiometric regardless, SU carbs (constant depression) probably not too rubbish and in last place you have things like slide carbs and webers.

I think you’ll find that modern cars are much cleaner on idle, startup, and warm-up. Carburettors can work very well once you get the engine warmed up and are cruising at constant throttle, but they struggle at low revs and when the engine is cold. Given that most urban journeys are fairly short, that makes a huge difference to air quality in cities.

It depends on the design. The reason SU carbs werr so popular is they work very well in those normal conditions. Effectively they are automatically adjusting the venturi size to give the optimum pressure drop. Their drawback is precisely that though, they always have a pressure drop.

Compare that to something like a slide carb which relies on the driver/rider directly controlling the venturi with the needle fixed within it, or webbers which had two different sized chokes and progressively opened one then the other. Both then rely on seperate idle jets and accelerator pumps to enrich the mixture when the SU handled it automatically. The upside was you could open the throttle wide and have lower pressure drop at high RPM on the race track.

Depending on the setup the catalyst probably makes the most difference, they appeared long before fuel injection and can work with carberators, they just need a bit more carefull setup as well as things like EGR to reduce NOx emissions.

Even modern cars aren't always stochiometric and even when they are the mixture may not be stochiometric all through the cylinder. So you still need measures in the exhaust to clean it up. Which is why following a boy racered VAG/Ford/Subaru it smells like its from the 70s, even with fuel injection.

My first and current cars are VW golfs. The 1977 Mk1 compared to my Mk 7.5 had 1/4 the of power, a little less than 2/3 of the weight, a four speed gearbox more than double the official 0-60 mph time yet the newer one is at least 25% more efficient in terms of fuel consumption. That’s what 40 years of progress does.

Just look at one, admittedly fairly dark, cultural trope from the 70’s and 80’s – gassing yourself by running your car in a closed garage.

Doesn’t really work these days, you would probably starve to death first.

Bloody start stop technology.

This, the most surprising thing about those empty roads during lockdown was that is wasnt “lowest ever traffic levels” but only the lowest since the early 1970s.

Seems surprising but when I think about it, maybe not so much.

'When I were a lad' at a guess about half the households in my street had a car, and that would be early 80s. Now when I look down my street I'd say about a 3rd have a single car (tend to be older people) most have 2 and some with grown-up kids have 3 or 4.

Despite the odd guide on 'starting your car after 3 months' or whatever, I get the impression at even at the height of Lockdown most people were going out most days, even if they only popped to the shop for essential purchases.

Add in the fact that there are 10m more people living in the UK now than in '75 and the Motorways were virtually empty at the height of lock-down, I'm less surprised that in-town traffic wasn't 70s low.

What I can’t really compare is emissions. I’ve looked online and can’t find anything related to vehicles from that period. I’m guessing but I’d say they were horrendous.

I think you'd be right. When you follow a vintage car from the 60s and 70s you can smell the un-burnt hydrocarbons in its exhaust. I grew up the 60s and 70's but never smelt it then- I guess we were all desensitized to it because it was pervasive in our environment. I reckon if we went back in a time machine to that period the cities would smell like petrol refineries to our 21st century noses.

My first and current cars are VW golfs. The 1977 Mk1 compared to my Mk 7.5 had 1/4 the of power, a little less than 2/3 of the weight, a four speed gearbox more than double the official 0-60 mph time yet the newer one is at least 25% more efficient in terms of fuel consumption. That’s what 40 years of progress does.

I don't think it's as stark as you make out TBH.

Engines have gotten much bigger for one thing, back in the 70's a 1.1l engine was common, these days it's considered small even with a turbocharger vastly increasing its effective capacity.

For example, the BMC 1500 engine of the 1970's that was fitted to a lot of small sports cars and midding sized saloons and hatchbacks produces about 66 HP, the last of the non-variable valve, non-Turbo Ford Zetec-E 1.6l engines produced 100HP, and a significant chunk of that was produced above the BMC's redline, so really it's not so much improvement in torque, but in materials and manufacturing, the Zetec has more crank bearings, split forged powdermetal con-rods, 4x valves (i.e. smaller and lighter) per cylinder, overhead valves (no pushrods) and other improvements which basically lift the rev range of the engine.

Similarly, a GT6 produced 105HP, a Jag AJ-20 produced 160. (2.0 Vs 2.1l), but again the jag engine had about 20% more rev's.

Fuel Consumption – I would have said about the same for small/medium cars but admit over the last 10 years we have seen improvements at the cost of complexity.

Really? As TMM said, I remember 30-35mpg being something to boast about. A mate of mine had a (granted 3 litre) Capri which did about 8 to the gallon. With the right car and a bit of careful driving you could probably get close to three figures that today. When my 2L Octavia went back it was showing a total average mpg of about 50 IIRC and that's with me sticking it in "Sport" and leaving it there.

Power – Amazing improvements, my Hillman Imp had 33bhp to start with (but even in rally format it had less than 60) and now something like a Corsa is close to 100 with a 1.2 turbo.

It's more than that, Ford's Ecoboost engine is getting like 125HP out of a one litre engine. They put them in bloody C-Maxes for heaven's sake!

the handling was dreadful – it understeered terribly when pushed.. or so I heard *ahem*

Schoolboy error. That's what the handbrake is for.

Schoolboy error. That’s what the handbrake is for.

That theory was also tested and found wanting.

I think you’d be right. When you follow a vintage car from the 60s and 70s you can smell the un-burnt hydrocarbons in its exhaust. I grew up the 60s and 70’s but never smelt it then- I guess we were all desensitized to it because it was pervasive in our environment. I reckon if we went back in a time machine to that period the cities would smell like petrol refineries to our 21st century noses.

Drive anywhere in Africa and you can experience it all again....

It’s more than that, Ford’s Ecoboost engine is getting like 125HP out of a one litre engine. They put them in bloody C-Maxes for heaven’s sake!

Yes, but that's playing top trumps, you can't pick and choose that starts you compare.

The ecoboost Ford's aren't very economical,

Your 2l octavia was I presume a diesel

Something more like for like would be an MGB Vs MX5, a B will do about 25-30 in the real world, MX-5 according to Fuelly does 32-35. ~20% better, but not the doubling you're implying.

And about half that improvement will be in aerodynamics rather than the engine.

I'd rather have an Mgb than a 1l ecobooost cmax.

The 2l ecoboost focus on the other hand.

In the early 60s my dad had an 850 Mini. Top speed 72, 0-60 25 seconds, about 26mpg. Most of that fuel must have come straight out of the exhaust pipe, or it would have made more than 28bhp.

thisisnotaspoon
Something more like for like would be an MGB Vs MX5, a B will do about 25-30 in the real world, MX-5 according to Fuelly does 32-35. ~20% better, but not the doubling you’re implying.

According to Fuelly the average MGB does closer to 25 and the most recent MX-5 is doing 40 in British gallons, so if that's right the MX5 is approx 60% more fuel efficient, despite being safer, quieter, lower NOX, better radio etc.

edit: maths not my strong point

There has been a huge improvement in fuel ecomomy and emissions.
From 1990* to 2018 road traffic in the UK increased by about 30%, while total greenhouse gas emissions from road traffic increased about 6%. Total fuel used remained pretty much the same.
* I can't entirely be bothered to search for the equivalent data for the 1960's / 70's but would have thought that there were improvements between 1960 and 1990 as well.

SU carbs were brilliant at the time. My Imp ended up with a pair (and no they weren't Strombergs - I had the manifold made at CT Conversions in Croydon) and if it did less than 40mpg there was something wrong with it .....or maybe I was giving it a bit of stick 🙂
However even with a return of 40 I bet the were terrible. Be interesting if someone posted a few tests on You Tube but they don't seem to exist.

I'm going to disagree with 30-35mpg being something to boast about - in the 80's my Golf Mk2 GTI returned 38mpg which is exactly the same as my current Mk7 so no improvement there except for 100+bhp.
The one thing easily overlooked is that cars have gained in weight significantly.

I don’t think it’s as stark as you make out TBH.

Engines have gotten much bigger for one thing, back in the 70’s a 1.1l engine was common, these days it’s considered small even with a turbocharger vastly increasing its effective capacity.

The Mk1 golf motor had 1588cc, naturally aspirated with a single Solex carburetor (with an automatic choke) , single OHC and made 75bhp and did about 28 mpg over the three years I had it. It also needed oil changes every 6000 miles. The next car I had after that had 1570 cc, naturally aspirated on two twin choke Weber and DOHC and had a (probably generous) official 115bhp. Yet that would still do about 30 mpg. So capacity even at the time wasn’t a great guide to output or efficiency there were so many variables.
The Mk7.5 has 1984cc, a (large) turbo, variable valve timing and fuel injection, a catalytic converter etc.etc. It has oil changes every 17-19000 miles if on the variable service regime. In a car as light as the Mk1 it would have an MPG of 45 or more I would imagine so a 50% plus improvement and a much lower emissions output. But it is also immensely more complicated but ( so far) more reliable.

Just found this on the SMMT website:-

It would take 50 new cars to produce the same amount of pollutant emissions as one vehicle built in 1970 (Defra)

The ecoboost Ford’s aren’t very economical

My Focus Estate Ecoboost 125 does about the same mpg (45 average) as my previous Focus Estate 1.8TDCI. The technology in the Ecoboost is a bit bleeding edge for a production car, though. Any coolant problems and they overheat and die before you notice. The timing belt runs in an oil bath, quiet and efficient but sheds fibres into the oil which clog the oil pump. It was intended to last the life of the car but Ford now say 150k and others suggest 75k; the book time is somewhere about 12 hours to change it.

suggest 75k

Otherwise known as the life expectancy of a headgasket on an 60s/70s car. And about 3 times that of your plugs needing gapped.

@Greybeard - I had a Renault Scenic (one of the early designs) and the service interval was 15K but the cam belt needed replacing every 12K!

Back in the 1980s I had a Vauxhall Cavalier 1.3L, typical MPG was around 30. It's worth remembering that many of the engines of the time were decades old - my first vehicle (1979) was a Morris Marina Van, again a 1.3L engine but that B-series engine was from the mid 1950s

It would be interesting to retrofit a modern Golf engine to the original and see what the fuel consumption would be like. You'd probably have to trim the power a bit otherwise it would be a bit "flighty"!

It would be interesting to retrofit a modern Golf engine to the original and see what the fuel consumption would be like. You’d probably have to trim the power a bit otherwise it would be a bit “flighty”!

Someone is fitting a Golf R drivetrain into a Mk1 Golf, Project Binky style. Might prove interesting....

There are YouTube videos of some madman in a (modified) mk1 golf absolutely blowing away some genuinely quick cars.
I agree about weight, look at a caterham for example, 90bhp in one of those is bloody nippy up to normal speeds.
I’d like to see a normal hatch (like a corsa) made truly lightweight, carbon shell, lightweight wheels, seats, everything. 60-70bhp would be absolutely plenty.
My dad had a 1979 fiesta 1.1 popular.
Iirc, 55bhp, top speed must have been around 80mph, but it did about 40mpg all the time even on carburettor, and had no problem at all keeping up with traffic.
Probably only weighed 750kg though.

Yes, but that’s playing top trumps, you can’t pick and choose that starts you compare.

The ecoboost Ford’s aren’t very economical,

Your 2l octavia was I presume a diesel

It was, yes.

Fair point and one I hadn't really considered. Even so though, any single one of those criteria would have been inconceivable in the 70s.

My dad had a 1979 fiesta 1.1 popular.
Iirc, 55bhp, top speed must have been around 80mph

55 is right or not far off I think, if you'd asked me cold I'd have said 56. I had a 1.1 also, a 1977-vintage L. You could tell when you hit an (indicated) 80mph because the glove box started throwing cassettes at me. It was quite nippy for what it was though, probably because it'd had a non-factory modification to have it lightened (ie, rust doesn't weigh much).

Astonishingly there was also two smaller-engined variants, a 950 in high-and low-compression offerings. The US got one with a 1.6 block, no idea what that put out.

Back in the 1980s I had a Vauxhall Cavalier 1.3L, typical MPG was around 30.

I had a string of Cavaliers, I bought a 91-plate and fell in love. One was an SRi, that was an 8-valve 2L petrol block putting out 130bhp. By comparison my current car is a 1.5L which is 180 horses.

a manual choke

Lucky you. The auto choke was dreadful.