Re: Terrible mileage 99 GLE

Ralph Hertle wrote:
> Dave:
> 
> David Geesaman wrote:
> [...]
>> I've done two years of serious research tracking my fuel economy.  I 
>> used only 93 octane for several years before switching to 89.  My fuel 
>> economy did not change at all.
>>
>> I imagine under very heavy load there is a difference, but for routine 
>> driving you will not see anything.
>>
>> Dave

> A higher rated fuel than what the manual recommends has no effect on 
> power or fuel economy. Nor does it have any additional quality. Higher 
> rated fuels than necessary are simply money wasted.
> 
> Ralph Hertle

Yes Ralph, all that is true and well-known.  However, the Maxima's knock 
sensor will trip if you run lower octane fuel and adjust timing.  The 
net result can be loss in both power and fuel economy.  My experience, 
sup****ted by the data I've collected, is that stepping down from 93 to 
89 octane has not caused the computer to adjust and lose fuel economy.

Also, fuel economy wasn't the only thing I was interested in learning 
from tracking my mileage - I also know exactly what I'm spending on fuel 
per month and how many miles/day I drive.  Makes oil changes very easy 
to keep track of.

Dave