What's the lowest weight I can go in my 85 GL-10? Lookin' to maximize fuel economy.

Heh. You should not go any lower than recommended in your manual - which is 10w30. Going lower may help you mileage very slightly - at a much higher cost in engine wear. If you want economy then sell the turbo and get one with an NA engine. Turbos don't respond well to attempt at super high economy. They need to run rich to prevent detonation and bring down exhaust temps. Poor mileage is a hallmark of owning a turbo and it something you learn to live with..... Or blow up engines.

 

GD

Thanks General. I'm getting about 25mpg I believe.

That's very good for a turbo automatic.

 

I get a solid 16.5 mpg in my '91 2.2 turbo SS. And it only drinks premium.

 

GD