JimD007
Active Member
It is reasonable to try 89 octane and it might have advantages but in my other car, a normally aspirated BMW convertible with a 3 liter 6, I get better mileage with 87. Most people think I am anal but I write down the miles, gallons, and cost each fillup. I have over 100K miles on the convertible (one reason I now have a truck) and used 89 for about 50K miles of it. I get slightly better mpg out of 87. That makes some sense because the higher heat value of gasoline actually goes down with higher octane. The available energy in the fuel goes down. But if your engine has to retard timing to avoid pinging on the lower octane fuel your mpg can go the other way. So a trial is in order. But you need to be careful and record miles and gallons for several tanks both ways. I did over 10,000 miles with 87 before I was convinced the couple tenths of a mpg was real.
I really doubt your truck is pinging on gas it is recommended to be able to use. It isn't impossible, my old Suzuki SUV would do it on a hard pull especially when it was hot. But most cars run fine on the gas the manufacturer recommends for it - they should. And if they don't it seems like it is something the dealer needs to fix.
I really doubt your truck is pinging on gas it is recommended to be able to use. It isn't impossible, my old Suzuki SUV would do it on a hard pull especially when it was hot. But most cars run fine on the gas the manufacturer recommends for it - they should. And if they don't it seems like it is something the dealer needs to fix.
