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I've been reflecting on how the Prius and other hybrids supposedly reduce the wear from frequent engine starts by using there powerful motors and batteries to rev the engine at or near idle speeds before supplying fuel and spark.

Recently, I've tried bump starting the Elantra (2002, manual) by putting it in gear with the ignition off to turn the engine around 1000 rpm and then turning the key to on to supply the fuel and spark. The result seems smoother than the way I used to bump start (ignition on, then release clutch to turn engine) or starting the engine with the key.

Is this the way that some have been bump starting their cars all along? Do you have any information on the comparative costs or benefits in terms of emissions, component wear, or fuel consumption?

interesting find.. its a shame i don't have a chance to test that theory.

As a big time bumper.

Why waiste the entgy to spin the engine? I would think its a waiste to use energy to spin a engine when I could coast 100 more feet with that energy.

At higher speeds I bump off in 5th gear. Slower speeds 2nd, 3rd and sometimes 4th. Just depends on conditions, speed, traffic, terrain and so forth.

I would rather bump with the ignition already primed and ready to go. Otherwise I think any savings in engine wear would be offset by increased clutch wear. I can usually get it to catch after extremely brief clutch contact, whereas spinning first would basically mean dumping it. Not to mention the fact that bumping with the ignition on is fast, whereas bumping then keying could take quite a bit longer. Even a couple of seconds delay is too long to have to wait IMO.

Now that I have my injector kill switch, I don't even have to key off so my ignition is always on. I can go as slow as 10 mph and still start the engine in 5th gear by a quick out then back in with the clutch pedal. At that low speed, I then have to grab 2nd or 3rd to speed up.