Octane requirement

[Ramblin Fever]

Ok, I'm confused now.

My understanding is that the SOHC 3.2L V6 95.5+ engines have a 9.0:1 compression ratio??

A little history 1st off, so y'all know where I'm coming from on this. I bought this truck in Vegas, NV with 12K miles; lowest octane out there is 87. Truck always pinged in the summer heat, whether flat land or not.

Several times I took it back to the dealer and they reprogrammed something (can't remember now), but also stated to use higher-octane, although the manual says 87 minimum.

I did try higher octane, think 89 maybe, however I don't recall doing that for long, maybe 2-3 tanks before going back to 87, assuming higher-octane wasn't working. I know now that I didn't do it long enough.

However, I didn't feel the need to investigate further, as when I moved to Denver, CO the pinging would always stop half-way thru Utah. I've since learned that in higher elevations, you're vehicle requires 2 pts less.

However, I ran 70K of my 123K miles on an octane that I believe was too low; I didn't have loud, excessive pinging, but it was definitely there on days 100+ degrees.

Truck is still running beautifully, however still using 87 and just yesterday, noticed a little pinging. Do you think there was any engine damage sustained?

I'm switching to 91 octane, at least for summer.

What octane do you all use??

[amigo-2k]

I was using 90 due to pinging with 87. But with the gas prices I went back to 87 with no pinging.

My previous truck (S10), ping'ed for about 100k of it 181k life. I sold it 3.5 years ago, and I just saw it driving around last week. So it is still kicking after 18 years.

-Ryan

[rheteric]

I was thinking of going back to 87, from 89, which would probably cause the pinging to come back again, but with gas prices skyrocketing lately the reality is that the higher octane is actually a better buy now than it was a year ago.... relatively speaking. Maybe I'll switch to 93.... what the heck, right?!?!?!

[mospeed1]

mine pings hard with 87

[Cat Fuzz]

My 94 3.2L runs just fine on 87.

[rodeo02]

I run the least expensive gasoline I can find, always have. Not too easy these days! Just over $2.00/gal here in Buffalo NY for 87oct . My 2002 has always pinged loud for a few seconds if you FLOOR it, have it under high load of going up a STEEP incline, etc, etc. It's annoying, but normal detonation. Your 3.2L will wear out from high mileage long before *some* spark knock will kill it. I have however noticed that ethanol blended (10%) gasoline takes even the light ping away.
G/luck
Joel

[Ramblin Fever]

Rodeo02 - Curious, what do you classify as "high mileage" on these 3.2L??

[rodeo02]

Originally Posted by Ramblin Fever

Rodeo02 - Curious, what do you classify as "high mileage" on these 3.2L??

There's 3.2 owners out there with 200,000 miles on them.

G/luck
Joel

[amigo-2k]

Here is a good post on highmileage Zu's:

http://www.4x4wire.com/forums/showfl...=&fpart=1&vc=1

[Ramblin Fever]

Great, wonderful!! That's what I want to hear - I love this truck!