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Volting - A Technique of Traveling With Your Engine Off – Mike Mas

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As we've told you before, posting the same thing in two places on this forum is inappropriate.

It looks to me like your "Volting" is basically the same as the mountain mode games folks have been trying for several years. Some times you can come out ahead by a little with them, but mostly it comes out the same as letting the car drive itself for fuel consumption, and it can be worse in some scenarios, especially if you end up doing the mountain mode based charging at high freeway speeds or while climbing hills.

A Mountain Mode cycle means incurring the conversion losses to electricity on more of the energy, and paying for the battery charging losses as well - it can only come out ahead if it allows you to operate the engine at a more efficient point (which is possible, if you choose your timing carefully, but won't happen by chance anywhere you might use it.)

Different things may be important to different people, but "engine on miles" isn't a consideration for me. I care about fuel efficiency and about engine noise - but if running the engine most of the time at low rpm is more efficient on a trip I can't avoid using gas for, I'd do that.
 

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Just to set the record straight, I never doubled posted my article - since the story was for ELR's and Volts, I posted it once on the Volt discussion forum and once on the ELR discussion forum. The reason is because its unlikely that a ELR user would visit the Volt forum and vice versa.

Multiple posting is generally placed by someone selling something - I'm not selling anything, I'm just another Volt owner like you guys who enjoys his car and enjoys learning and sharing information with other owners!

Thanks
I guess double posting means different things to different people. The article appears twice at the top of this thread because you started two threads and both already had comments when I saw them, so I merged them.

As you and WopOnTour have been discussing, the double posting that we were objecting to was the posting of two threads in two parts of the forum with the same content - something we've discussed before that is still against forum rules in this and most other forums I've seen.
 

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Congratulations and Thanks Mike for that publication. It is pretty simple to understand that this is profitable on long trips. You went beyond what Gm were saying in the books and found a way to make "mountain mode" usefullnes.

JJ
No, it isn't - which is one of our fears in leaving this thread as it is, and the reason for the unprecedented moderator note added to the initial post. If you read any of the posts by senior members in this thread or that note, you'll see that this technique isn't a simple solution for all situations - a lot of us have experimented with it and studied it for several years now (though without a fancy name like Volting - if you want to see the older threads, search for Mountain Mode Games,) and it only gives you gains in certain conditions.

It can result in some mileage gain, if the terrain and timing of the engine on cycles works out (to come out ahead, you need to be driving at a relatively low freeway speed, and you need your engine on sections to be flats or if you can manage them downhill sections.)

However, you're most likely to come out about the same or just a little worse than the car's default programming - and if your engine on sections are the up hill portions or you drive at higher speeds (like 70 mph, say,) you'll use significantly more gas than you would if you'd let the car make the decisions.

Whether you gain anything is all about where the engine falls on the BSFC chart and how much power you can put to the road mechanically. The closer to 2500 rpm you can keep the engine, the better - and the more power you can have go directly to the road instead of going to a generator and then back to a motor (~15% losses for the round trip) or worse to the battery and back (another ~7%) the further you go on the same energy. Of course, the slower you drive the less you use, too.

Don't let the unrealistic assumptions baked in to the pretty graph fool you - or the improbable suggestions about just doubling the mileage you see (which would imply that the car would charge the battery slower if you drove slower - the reverse is actually somewhat true.)
 
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