Up Hill!


Dave wrote to Rob - My son complained to me that his 73 Super Beetle didn't go very well up the steep hills -- he slowed down to 35 mph a time or two, he said! I had to remind him that he's driving a Volkswagen -- it has just two speeds -- up hill, and down! :-)

Rob responded - Yes. With the light body weight (under 2000 lb) it runs quite well with around 60 hp, but in hill climbing the lowish power IS noticeable. The equivalent 1600cc Nissan or Toyota might be a little heavier, but they have around 80-100 hp, and the difference in hill climbing ability is noticeable.

The correct technique with the VW engine it to change down to 3rd before you loose too many rpm - say as the speed drops below about 45 mph on the hill, and the higher rpm in 3rd will help maintain the speed better, and also helps keep the fan spinning fast for better cooling -- important on long hills of course.

Being a short stroke engine (undersquare) it's not especially torquey like a "square" or "oversquare" engine is, so you need to use the rpm to maintain power.

Porsche apparently designed the engine that way for three reasons -- it keeps the piston speed relatively low for better piston ring life, it makes the engine a "free revving" engine (unlike most 1930s engine designs), and it also kept the engine narrow, which is important in a flat engine, so it will fit in the car. (the 1000/1200cc engines are 64mm stoke, and the 1300/1500/1600cc engines are 69mm stroke, making these engines about 10mm wider - 5 mm extra stroke each side).

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