98_z28

My car does not pull as strong as it used to and my valves chatter bad. . .does that sound like my timing could be off ??

Ego Killer

iTrader: (147)

no, sounds like your running cheap gas.

406malibu

which would lower timing due to the knock sensor

NoE~DaWg

dang, my car is doing the same thing and come to think about it, it started when gas prices started going up and I stopped pumping 91 and started pumping 87...I can't believe that makes so much of a difference.

fuseone

owners manual says you can use 87 but performace will be different.

Ego Killer

iTrader: (147)

back when mine was "stockish" it ran like a$$ when I used 87

NoE~DaWg

lol guess I should fork over a few extra bucks and pump 91. I was gonna have it tuned cuz I thought that might take care of the pinging. I'll run 91 the next few times I fill up and see if the pinging stops.

ItsNotStock

iTrader: (24)

I have never understood why people think using cheap gas actually saves money in the end. Up here premium (91) is $4.29 and midgrade (87) is $4.21. That is a difference of eight cents... yes eight cents. On a full tank of fuel that would equate to $1.20 I don't know about you but the extra buck is worth eliminating the pinging, and suffered performance. Unless you're tuned for something else the recommended octane for these cars is 91+ if you can't afford the extra dollar than you shouldn't have purchased the vehicle.

OP, run a scanner and see if you're getting KR. Honestly it could be a number of things mechanical. What did you do to your car recently? Any error codes? Start fueling up somewhere else and see if it goes away. It's not too uncommon anymore for gasoline stations to high-grade.

Luder[PAK9]

Well, it's more like a 30-40 cent difference on the coasts. But you're right. If you didn't want to spend $$$ on gas, you shouldn't have bought a 5.7L V8.

gymratt

iTrader: (3)

+1

burnrubr88

iTrader: (2)

plus since the engine was made to run on 91 or higher it will perform better and be more efficient, and the improved efficiency from the higher octane will end up saving you money in the long run (i.e. more efficient nets better MPG in most cases)