Sudden MPG increase

[MagnusTheBrewer]

I recently replaced the clutch on my 1986 Mystery Machine (Chevy G10) and gas mileage has mysteriously increased by 2+ mpg. Is it really possible to gain that much efficiency with just a new clutch?

 

[LTC8K6]

Sure, if the old one was slipping a little.

 

[Yuriman]

The weather just got warmer here and my gas mileage jumped dramatically.

 

[LTC8K6]

That too. Could also have switched fuel blends in your area.

 

[Crono]

The weather just got warmer here and my gas mileage jumped dramatically.

Same here. Was hovering around 35-36 mpg combined, and now it's up to 38-39 mpg.

 

[Drako]

Summer vs Winter gas?

 

[Yuriman]

Summer vs Winter gas?

In my case it's just air temperature. Cold weather causes reduced gas mileage for a variety of reasons, even outside of gas blend.

 

[MagnusTheBrewer]

Not a gas issue or, weather. My mpg has definitely improved. It's an old beater with a bad engine/transmission combination that has always sucked. The 305 V8 was never a good power plant for Chevy but, now a 29 year old van is suddenly getting another 2+ mpg. I'm starting to think it's aliens.

 

[tortillasoup]

Aside from buying a new battery, cleaned up battery terminals/disconnecting and reconnecting them, could have a vacuum leak.