Poll of the Day > Any time I see cars from like the 70s and earlier, the exhaust stinks really bad

(+) Yeah! (+)

And I think, is that just how cars were then, or is it just because they're old and don't work as well? If it's the former, those must have been some really stinky times. How the hell did people put up with that and think it's okay?

The lead fumes really took the edge off

July 1992 mandated catalytic converters and unleaded in the EU, so it's hardly surprising old, inefficient engines would produce awful emissions.
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First of all, they weren't fuel injection, so they didn't have the precise computer controlled measurements of fuel to burn in relation to air (which on a modern car is accomplished through many variables, generally Air Intake Temperature, Mass Air Flow, Manifold Absolute Pressure, Throttle Position, and then the accuracy of this data's result is adjusted and double checked by your Oxygen Sensors), you were just kind of guesstimating air/fuel by vacuum pressure back then. (Lawnmowers and chainsaws operate the same way as really old carburetor cars, because it would be extremely cost inefficient to fuel inject a $50 leaf blower.)

Second of all, there was no such thing as catalytic converters (and at the very least was not a legal requirement), which converts a lot of dangerous parts of exhaust such as Carbon Monoxide into Carbon Dioxide and things like that to be less harmful to your body and the Earth. It also helps absorb unburned fuel that accidentally escapes during the exhaust cycle.

And not to mention, likely used different leaded fuels like the two above me pointed out.
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I just wonder if people driving those things around are aware of how bad they are. It's one thing if you have a classic car, but most of the time it's just some ugly clunker.

Also, that's a nice explanation. I had a vague idea of fuel injection and catalytic converters and whatnot but didn't really think about it

Although wouldn't those cars be using all unleaded fuel now? So obviously that isn't the main issue

Don't most states have emissions testing laws now? If it was a real problem, I think it'd get caught by that.
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just gonna say....
yall taking about leaded fuels being a part. you are aware you cant buy that now right? thats not whats making that old car smell.
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Zeus posted...

Don't most states have emissions testing laws now? If it was a real problem, I think it'd get caught by that.

I think with an antique plate you can get away with it.

Also, in my state, we have no laws. I have race-car full long headers to a catless Y-pipe with absolutely no emission correction of any kind. No EGR, no AIR pump, no catalytic converters, nothing. It is totally illegal for any state emission wise, but it isn't illegal to own or install. I'm going to get a catalytic converter welded in at the very least, eventually, because I don't plan on staying in this state. I can pass a scan test, but a visual or sniffer test is very grey area for me.
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NightShift posted...

just gonna say....
yall taking about leaded fuels being a part. you are aware you cant buy that now right? thats not whats making that old car smell.

You used additives with the unleaded fuel if you really want to stay true to form. But it likely doesn't have any effect on the smell, you're right.
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http://aircarecolorado.com/index.php/consumer-information/collector-plates

Apparently these are the restrictions for Colorado. I swear that not all of them have those plates though. Based on the second bullet point, I think that most of them must be grandfathered in and not have to re-test. I didn't know there was a mileage restriction, but I was thinking that's a good idea. Though 4,500 sounds kind of like a lot to me; if you don't have a long work commute you could still use that as your "regular" vehicle. I average about 6,000 a year

SteamedHams posted...

Although wouldn't those cars be using all unleaded fuel now? So obviously that isn't the main issue

Lead was for increasing AKI/RON. This was basically swapped with ethanol, but ethanol damages rubber so it can harm classic cars. Chances are the smell is poorly-burnt fuel from bad air/fuel ratio and NOX from high heats from running lean.
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SteamedHams posted...

I average about 6,000 a year

6,000 a YEAR? lol. I didn't realize I drove that much... I took my car from 30,000 to 73,000 in 2 years.
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Well, I don't think I'm a good baseline, but ~20k a year didn't seem like much to you before? I believe most people average like 10k a year

SteamedHams posted...

Well, I don't think I'm a good baseline, but ~20k a year didn't seem like much to you before? I believe most people average like 10k a year

6k in England.
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SteamedHams posted...

Well, I don't think I'm a good baseline, but ~20k a year didn't seem like much to you before? I believe most people average like 10k a year

To be fair, I had done some out of state traveling and Hurricane evacuation in the last 2 years. I suppose my in town average would be lower.
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Man, when you average any of those numbers out per day it sounds like so much. Even my figure of 6,000 is 16 miles a day. I imagine the vast majority of miles I've put on my car since owning it were going to and from work, but at most I lived about 8 miles from work. So that number would almost make sense, but then I gotta factor in not working every day, living in places closer to work and not having a job for over a year, and it seems like such a large number. I guess going to my parents' house added a lot of miles too, that was like 20+ one way from most of the places I've lived, but it's still a staggering number to me.

Something to consider with mileage is also what kind of mileage. An overdrive gear on the interstate for long periods of time is the best mileage for your car, because physics is on your side and you are largely coasting. Your engine barely has to do any work at that gear ratio and speed, (overdrive means your engine is spinning less than 1:1 with your transmission/final drive/wheels). Stop-go-stop-go is much harder on your car. (Moving 2,500-6,000 pounds from a dead stop is a lot of work.)
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