Is it okay to use Octane 90 for Opel Vectra 1993 ?
I had changed the Octane from 95 to 90 a year and half ago , and now I feel that there something wrong
with the engine , there is a strong vibration on neutral, and sometimes if I am on hill and I stop , it barley
moves especially if it stays too long time on the neutral position .
so I tried to mix the 90 with 95 , will it work , or is it a waste of money ?
Thank you in advance !
Depending on th milage I don't think it has much to do with the gas. I would maybe start with a good tune-up. An engine flush will clean built up deposits and generally restore power. Whenever I plan a trip I fill up with ethanal free gas and add a galloon or two of high actane racing fuel from the local gas station, or a can of sea-foam. after a couple hundred miles the engine runs straight as a laser.
Thank you for you answer Joseph , as you mentioned I think that I should start up with a good tune up , but I have to mention that I live in the middle east so I have never heard about the ethanol free gas and to be honest I am not sure if the gas station have it here :S so do you think that after the tune up ,should I continue mixing the 90 with 95 ,or not ? Thank you !
Personally, I think 90 octane is fine for your vehicle. I'm not sure if ethonal is mixed with gasoline in the middle east. It is added at the refineries here and is derived from corn or other plants which will ferment and form ethonal. I use a product called Sea Foam and flush my own engine. If you have a PVC, pour some into it and into the fuel body until it begins to stall and turn off the engine. Pour the rest into the gas tank. Let the engine sit for 15 minutes. When you start the engine back up it will blow white smoke for a few minutes. Drive it until it clears. It will do a good job of cleaning engine deposits and your injectors.
Thank you Joseph for your advise this is really helpful, I appreciate it :)