I've been wondering to some point paranoia kicks in for a while...
So my AE92 4AF has been running 93 octane (Shell V-Power or ExxonMobil). Shell just started mentioning their nitrogen enriched gasoline. Before that, they added more ethanol. They say nitrogen will result in cleaner combustion chambers, clean and lessen intake deposits.
My question is: What effect does that have on an engine that is 21 years old with 230k miles?
About the paranoia part. I've always thought and still do that they'll try to refine gas with additives so it can inconspicuously kill older engines due to emission purposes.
About the paranoia part. I've always thought and still do that they'll try to refine gas with additives so it can inconspicuously kill older engines due to emission purposes.
Why would they want to kill older engines, and how would they differentiate between who is using which gas? Newer engines are built with tighter tolerances and more precise parts, requiring better fuel. Sorry, but that doesn't really make sense.
as for running higher octane in the 4af. The compression doesn't require it but if your carb is acting up it's a good way to get it running better. I know because that is what I did when I first got the car and the carb was dirty as all hell.
Only majour difference than the car running nicer was I noticed the tank didn't last as long, but that is just because the higher grades usually have more additives. So you are paying more for less fuel per liter.
On the 4af and any other carb'd car the fuel travels through the intake, also on some cars the injectors are in the intake, not the head. Regardless either way the injector will be before the valve meaning it is going into the intake or runner at some point.
I can't see why it will hurt the engine. If anything all I have noticed with having an older car is having to watch what oil I use vs a newer car. Different types of seals and on top of that they are older so have the tendency to leak more if the oil's viscosity only just meets what is shown on the bottle.
They are right, you are paranoid. If anything domestics in particular aren't designed to last that long anyways. But that is the car manufacturer not the gas companies lol. If you really think of it they would like the older cars better as they burn more gas than the modern equivalent.
Can't go to lower octane. Tried that when the gas prices skyrocketed. The engine started knocking and thought my cam lobes were gone. Its been running hi grade the day it was new from dealer.
That's the thing DCM. I know newer engines have tighter tolerances. And all those emission crap so the vehicle emits lower pollutants. Thus, better gas formulation. They're adding all these stuff to allow the engine to perform better and always thought what happen if they formulated the gas too good for older engine. Just so older cars, which pollutes more than newer cars, off the road. And then we all buy new (or newer) cars.
I'm not PARANOID paranoid, just slightly. Given the fact that I could careless about gas or converting the ae92 to run on corn and apples. I just don't want to find out the gas being the culprit to be the reason my engine goes. Heat it up too much or something.
Depends, a guy at the meet was telling me what someone did to his 4af, Blocked part of the egr valve system and messed with the timing and he could only run high octane in it. If he has those problems running 87, it could be someone has done something to it in the past.
Depends, a guy at the meet was telling me what someone did to his 4af, Blocked part of the egr valve system and messed with the timing and he could only run high octane in it. If he has those problems running 87, it could be someone has done something to it in the past.
Rookie_One already said it properly:
Quote:
Originally Posted by Rookie_One
and if the engine is knocking when you go to Octane 87, either :
1) : Open it and Clean it
2) : Retime it
And to reiterate what half of the people on this thread already know: octane ONLY refers to detonation resistance. Nothing else. Nothing about power, cleanliness, emissions, etc....
higher octane burns slower... so you'll actually get less power running premium unless timing is adjusted to take advantage of it.
sounds to me that your timing is off.
and killing older cars off has no benefits for the gas companies... why would they do it? if anything they'd want to keep older cars around because they usually use more fuel.
that and all the cleaning agents and stuff are over-rated, just use some injector cleaner every once in a while and you'll be fine.
you're paranoid
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I noticed a slight response gain with the 4af on premium.. Probably because you are dumping the same amount of gas with more octane lol. But I don't think it was worth the cost.
Higher octane fuel won't do a thing for you unless your compression is high enough to take advantage of it. This doesn't necessarily apply to forced induction engines.
As for the timing being adjusted to compensate for high octane, that's not always the case. Take an older street bike for example, which has no means of adjusting the timing. If you run high octane fuel or even racing fuel, there is a very noticeable difference in performance, with nothing changed except the fuel type.
Even with my '87 Cressida, running 91 octane vs 87 made a big difference, both in performance and fuel economy. Running the 91 ended up being cheaper because I got better mileage and power.
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