Emissions and old gas

After recently getting my car going again I faced our lovely emissions testing here in CO. I probably had close to half a tank of old gas in it so I just topped it off thinking it might be okay. Yeah, not so much.

uploadfromtaptalk1459359016366.jpg


So that was fun. I'd never had any problems before so I drained almost all of the gas out and put fresh stuff in the old girl. Ah, much better.

uploadfromtaptalk1459359105691.jpg


The gal that ran it through the second time couldn't believe that old gas would make that much of a difference. Oh well, lesson learned.
 

NY Twin Turbo

All the good stuff.....Times 2.
It would seem you should copy these results into another thread in General Buick Turbo Tech.

It may help others understand how important it is to have good clean new fuel in their tank. There seems to be a lot of newbies that post up questions about problems after letting their cars sit for a long time. They don't seem to take it seriously how important good gas is until after they have had problems. This may help.
 

turbo chris1970

Engine bay
Wow great idea to post that ,especially us buick guys are a small group compared to all the other car guys and gals out there in the hobby and we need to help each other out with good advice to keep our cars on the road they are GM legends after all
 

Roc87

11 Second V6
Wonder if thats why my HC's were up? At least half the gas in my tank was over a year old, it did 399 of 200 at idle where 2 years ago it did 11! Won't ever run old gas while trying to pass again
 

b4black

Well-Known Member
Old fuel won't effect your emissions like that. Old fuel looses the light ends, making it harder to start and maybe hesitate when accelerating, but topping off with fresh will easily correct that.

This car failed big time on the first pass. I suspect it was something other than the fuel - like the catalytic converter wasn't hot enough. Or it needed a good, long heating up to burn off the junk that collected on it while sitting.
 
Wonder if thats why my HC's were up? At least half the gas in my tank was over a year old, it did 399 of 200 at idle where 2 years ago it did 11! Won't ever run old gas while trying to pass again
Yeah, you can see that the HC was high on my test. Literally the only thing I did was the fresh gas. Same drive to the testing facility. I got right in both times so there wasn't any big cool down period.

Sent from my SPH-L720 using Tapatalk
 

No disintegrations

Active Member
the old gas has less energy contained in it because the lighter components are gone. The combustion chambers and cat run colder because of that.
 

Heskahoka

Supporting Member
Amazing gas makes that much difference. Thanks for the write up, will remember that for my next emissions test.
 
Top