Does weather affect our engine?

[totaljoint]

I've noticed that my carburated 712 runs better (much better) on cooler, drier days in the fall than in the moist heat of summer. Top speed is 4 mph higher on the highway (she used to be happy at 58mph, now glides without pushing at 62-63). Hill climbs that I would have had to take in 2nd gear ony a week ago, she easliy does in 3rd.
I've been gassing up at the same places, same grade of fuel (87), only change here might have been "Stabil" I added to the last tank since I'll be driving less in the comming rain, but I use that pretty regularly during the spring too.

Some one told me that high pressure weather systems will put more O2 into a carburated engine, but even the biggest barometric change around here is worth only a couple of hundred feet on the altimiter and I've never noticed a change in performance from home at sea level to trips up to 3,000 ft.

Is "Stabil" the "Viagra" of the Pinz, or is the weather affecting the engine?

[spandit]

Colder air is denser so you'll get more into the engine than you would on a hot day. I'd also hazard a guess that the engine runs better because it's easier to cool down so more energy is sent to the wheels, but that probably contravenes one of the laws of thermodynamics.

Fuel is also denser at low temperature so perhaps it's sucking more in?

[edzz]

I've been gassing up at the same places, same grade of fuel (87)

If I remember correctly Washington changes to winter blend gas about Sept 15, could be what’s changed.

Ed

[Twin Pinzies]

I have often thought the same thing!
My trucks run noticeably better during dry/cool weather too. They also run better when driven every day. I have also noticed that Pinzgauers respond VERY well to certain fuel additives. Possibly due to their engines simplicity?

[totaljoint]

The Sept. 15 date sounds about right, Ed.
In fact yesterday I drove up hill (for those who know the cascades) Hwy 2 to Steven's Pass...in my 712 .... 68mph (GPS and Electric Speedo). Almost passed out when I looked at the gauge. And my foot was not on the floor!
I hope it's not like a light bulb, shines brightest just before it burns out.