Gas – 89 or 93 octane?
Question:
I read my owners manual on my 99 4.3 gmc sonoma. The manual said use 87 oct or higher. I don’t see why you should have to unplug your batt to reset your comp. The comp should able to adjust while you drive. I could be wrong, but what good is an on baord comp if it can’t "think" on the move. My opinion, Ross * Sent from RemarQ http://www.remarq.com The Internet’s Discussion Network * The fastest and easiest way to search and participate in Usenet – Free!
Response:
I,ve got a 97 5.7 runs on whatever I put in it no detention on any octane of gas under any load. A gm mechanic told me about disconnecting the battery if you were to change gas grades so the computer could reset itself and start from fresh i havn,t had to deal with that though – Hide quoted text — Show quoted text – >I have a 95 GMC Extended cab Z71 that has run 87 Octane gas from day >one. I have never had any pinging problems even when pulling a trailer >with 3 4-wheelers. >Hope this helps. >kmk > Hi all – > I have a ‘95 Tahoe and have been running it on 92 or 93 octane since >it was > new and it’s been running fine. Any time anyone sees me putting this >gas > in, they tell me 87 or 89 is fine and I’m wasting my money. > This week I caved and put 89 in and ever since the engine has been >pinging > under slight load. > Questions: > 1) Are there any real reasons to use 89 octane over 93, or vice- >versa? Am I > "wasting my money" putting 93 octane in? > 2) What causes the pinging? Is it something other than gas octane? I >let > the tank get really low before this fill up if this helps with >diagnosing at > all. > 3) Is it just coincidental that the pinging started when I put the 89 >in? > Thanks for any info! > – Bob (bobot) >Before you buy.
Response:
I have a 1995 Jeep Wrangler 2.5 liter, and it will barely do 75 mph with 87 octane. With 91 octane, it will do 85 mph. You may have to run a couple tanks of fuel through it before your vehicle computer learns the new octane. It should then stop pinging. Earle Horton Fort Collins/Silverton, Colorado – Hide quoted text — Show quoted text – > Hi all – > I have a ‘95 Tahoe and have been running it on 92 or 93 octane since it was > new and it’s been running fine. Any time anyone sees me putting this gas > in, they tell me 87 or 89 is fine and I’m wasting my money. > This week I caved and put 89 in and ever since the engine has been pinging > under slight load. > Questions: > 1) Are there any real reasons to use 89 octane over 93, or vice-versa? Am I > "wasting my money" putting 93 octane in? > 2) What causes the pinging? Is it something other than gas octane? I let > the tank get really low before this fill up if this helps with diagnosing at > all. > 3) Is it just coincidental that the pinging started when I put the 89 in? > Thanks for any info! > – Bob (bobot)
Response:
I have a 95 GMC Extended cab Z71 that has run 87 Octane gas from day one. I have never had any pinging problems even when pulling a trailer with 3 4-wheelers. Hope this helps. kmk – Hide quoted text — Show quoted text -> Hi all – > I have a ‘95 Tahoe and have been running it on 92 or 93 octane since it was > new and it’s been running fine. Any time anyone sees me putting this gas > in, they tell me 87 or 89 is fine and I’m wasting my money. > This week I caved and put 89 in and ever since the engine has been pinging > under slight load. > Questions: > 1) Are there any real reasons to use 89 octane over 93, or vice- versa? Am I > "wasting my money" putting 93 octane in? > 2) What causes the pinging? Is it something other than gas octane? I let > the tank get really low before this fill up if this helps with diagnosing at > all. > 3) Is it just coincidental that the pinging started when I put the 89 in? > Thanks for any info! > – Bob (bobot)
Before you buy.
Response:
I had a 94 camaro 3.4 and with 92 octane it ran better and got better gas mileage. I than leased a 98 GMC Sierra 5.0l and it didn’t mater what gas I ran the mileage didn’t change. I now have a 99 GMC Sonoma 4.3l and it seems to get better mileage with the 87 oct. but I haven’t had much time to tell for sure. * Sent from RemarQ http://www.remarq.com The Internet’s Discussion Network * The fastest and easiest way to search and participate in Usenet – Free!
Response:
I am not a gm tech or any tech to do with car for that matter. What I am is an electronic tech and always buy shop service manual with every new vehicle that I own. From the electronics perspective in modern vehicle, you are not suppose to changing gas octane in you vehicle. ie going back and forth with different grade gas is not good for the engine. Use the grade asked for in the owner manual, if you have been using the wrong grade and now wish to change grade, in your case to a lower octane. Disconnect the battery or the fuse to the onboard computer for at least 20 minutes to clear out the computer memory of the engine parameter with respect to fuel grade and weather. The computer will relearn to new parameter with the new gas grade to get rid of pinging. For computerize engine controls, higher grade fuel is only require for high compression ratio engine. – Hide quoted text — Show quoted text – > Hi all – > I have a ‘95 Tahoe and have been running it on 92 or 93 octane since it was > new and it’s been running fine. Any time anyone sees me putting this gas > in, they tell me 87 or 89 is fine and I’m wasting my money. > This week I caved and put 89 in and ever since the engine has been pinging > under slight load. > Questions: > 1) Are there any real reasons to use 89 octane over 93, or vice-versa? Am I > "wasting my money" putting 93 octane in? > 2) What causes the pinging? Is it something other than gas octane? I let > the tank get really low before this fill up if this helps with diagnosing at > all. > 3) Is it just coincidental that the pinging started when I put the 89 in? > Thanks for any info! > – Bob (bobot)
Response:
> Hi all –
Run what the manual says. The higher octain will prevent detonation (pinging) better than lower, but the new chips that control motors should be able to adjust your timing so that it doesn’t ping. Maybe it takes a couple of tanks…
Response:
If your engine doesn’t ping on lower octane fuel then yes you are wasting your money to pump in premium fuel. However, if you ping on lower octane fuel prolonged pining will cause holes in pistons, burned valves, overheating and reduced mileage and power just to name a few. In my area it’s about $2.00 per tank fill difference to use premium fuel. Lots cheaper than a new engine. – Hide quoted text — Show quoted text – > Hi all – > I have a ‘95 Tahoe and have been running it on 92 or 93 octane since it was > new and it’s been running fine. Any time anyone sees me putting this gas > in, they tell me 87 or 89 is fine and I’m wasting my money. > This week I caved and put 89 in and ever since the engine has been pinging > under slight load. > Questions: > 1) Are there any real reasons to use 89 octane over 93, or vice-versa? Am I > "wasting my money" putting 93 octane in? > 2) What causes the pinging? Is it something other than gas octane? I let > the tank get really low before this fill up if this helps with diagnosing at > all. > 3) Is it just coincidental that the pinging started when I put the 89 in? > Thanks for any info! > – Bob (bobot)
Response:
I experienced the same thing with my truck. I bought a new full size Z-71 in ‘97 (it was a ‘97 model) I wanted to use the best gas possible in my new ride, so I always used 91 or higher octane. After a year or so, I put some 87 in and my truck would ping at WFO throttle, I went back and refilled next tank with premium gas, and the pinging went away. Everytime I fill it up with 87 or even 89 octane, it will ping at full throttle. I don’t know if it will eventually go away after running a few tanks of 87-89 octane or if it will always require premium now. If you find anything out about this, I would like to know too. Matt in MI – Hide quoted text — Show quoted text – > Hi all – > I have a ‘95 Tahoe and have been running it on 92 or 93 octane since it was > new and it’s been running fine. Any time anyone sees me putting this gas > in, they tell me 87 or 89 is fine and I’m wasting my money. > This week I caved and put 89 in and ever since the engine has been pinging > under slight load. > Questions: > 1) Are there any real reasons to use 89 octane over 93, or vice-versa? Am I > "wasting my money" putting 93 octane in? > 2) What causes the pinging? Is it something other than gas octane? I let > the tank get really low before this fill up if this helps with diagnosing at > all. > 3) Is it just coincidental that the pinging started when I put the 89 in? > Thanks for any info! > – Bob (bobot)
Response:
Hi all – I have a ‘95 Tahoe and have been running it on 92 or 93 octane since it was new and it’s been running fine. Any time anyone sees me putting this gas in, they tell me 87 or 89 is fine and I’m wasting my money. This week I caved and put 89 in and ever since the engine has been pinging under slight load. Questions: 1) Are there any real reasons to use 89 octane over 93, or vice-versa? Am I "wasting my money" putting 93 octane in? 2) What causes the pinging? Is it something other than gas octane? I let the tank get really low before this fill up if this helps with diagnosing at all. 3) Is it just coincidental that the pinging started when I put the 89 in? Thanks for any info! – Bob (bobot)
