Gasoline, that is.

I mentioned earlier that I was experiencing pinging at partial throttle acceleration after I installed the JWT ecu. Eventually it went away. I thought maybe I had corrected an air leak somewhere, but I wasn't sure.

Well, the other day I went to a gas station I had been using about the time I installed the ecu but haven't been to in the last several weeks. After filling up on their 93 octane, I drove home, about a 20 minute drive. By the time I was close to home, my engine was pinging again at partial throttle acceleration!

Yesterday I refilled at a different station, and now everything is back to normal. So apparently that one station is selling something lower than 93 octane at 93 octane prices.

 

Yes, definitely happens all the time. Could be summer/winter mix(should be 100% winter now, but depends on stations volume), which reduces the anti-detonation value by AT LEAST 1-octane point.

Chevron is the ONLY station that is reliable IMO and keeps the inside clean.

 

the new bp/amaco stations seem to be pretty good.. here in GA anyway

 

That's just it. I only use Chevron gas. I thought I could trust Chevron, but apparently the honesty of the station owner is a factor.

 

Why didn't you say Chevron then?!?

Bad apple spoiles the bunch, so they say.

I wonder if you could "report" them, since they are SUPPOSEDLY regularly tested by the state or something.

Can't believe you guys get 93-octane still...all I get is 91-octane and it's 125F+ here in summer.

 

Bah. Notin but Amaco Ultimate for my baby. She gets the good stuff

 

Have you tried Shell? I've always had good results with their 93

 

shell, bp/amoco, mobil/exxon, sonoco--they're all about the same standards.


it the chocolate milk that the y serve over at citgo, speedway and clark that you have to worry about.

 

Surprisingly I've found that Arco has one of the strongest resistances to pinging/detonation whem compared to Texaco/Shell, 76, and Chevron.
Small trick I've found, look for stations who pump gas with 10% ethanol (all of the Arco stations I have been to use a 10% ethanol mix at the pump used to reduce emissions, but it has some added benefits).

To aviod bad batches of gasoline, you should never fill up while or just after a tanker truck has visited the station. What happens is the new gasoline washes up the debris and such on the bottom of the tank. Yes stations do clean these filters regularly, but still, it is a good rule of thumb that when the tankers there or leaving, hold off for for a bit before you pump.

If you are having detonation/pinging problems, find a station that uses ethanol in their gas, Ethanol burns cleaner and produces a higher octane ratings. (generally 3 points in a 9:1 mix).

 

Arco is crap! I've gassed up there once and my car almost died one time because of the crappy gas. Filled up at 76 and it runs fine. I like the Chevron/76 fuels. I've also be getting gas from Costco lately which seems to be pretty good.

S

 

Yes, and I've had to rebuild a 4.3l engine because it as filled up at BP/76 and had a bad batch, ran to lean, warpped a head, and destroyed 2 of the compression rings. That doesn't mean that all 76 and BP are bad. It was just one bad batch.

 

Yes thats a big factor. You never pump gas after the truck just delivered fuel. All the sediments will be lifted up and you will pump them into your tank.
I always use Chevron. Thats all she drinks!