I really appreciate your attempt to help, but as you recall from many
previous posts, pinging is a problem cured by higher octane fuel.
> No. This is not the only cure. Lower combustion chamber temps and less
spark advance are two other very popular cures.
I run 89 octane and the only time my Dak pinged is towing my trailer in
hot weather up hill. I added a bit of 'high test' and that cured the
problem.
I'm sure if a 180 thermostat was the cure, Chrysler would put them in the
truck from the factory.
I disagree. Ma Mopar (and all the other manufacturers) are all under
extreme pressures from the EPA et al to reduce emissions. The regulation
is strict. For example ... a cleaner running motor is a hotter running
motor. Your combustion chamber temps are higher to completely burn the
fuel charge, the EGT is high to keep the cat hot and and its efficiency
range, and the computers in ma mopars vehicles have always kept the
vehicles running on the fringe of lean (it all started with Chrysler's lean
burn emissions systems in the late 70's) All this to meet EPA pollution
standards.
The point here is that Chrysler has to build the most performance into a
vehicle, with the greatest amount of fuel mileage (so they meet average
annual mileage tables accross all product lines for the government), and
least amount of emissions. This is an extremely fine line to walk.
>From the other side of things ... you've got the EPA fighting emissions
with oxygenated gas. This is a complete and utter scam but I digress.
Anyway, the oxygenated fuel further lowers the flash temperature of fuel
making pre-ignition and detonation more of a problem.
I have had good success with my 97 on high test fuel but it still pings
under heavy load. Nature of the beast ...
Hope it helps!
Matt
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