Hybrids and OCI's

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Can you say unsprung weight?
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Ed
 
Hi,

I own a 2004 Prius and it does not indicate how much time the ICE is on so you just go by time or miles to determine when to change the oil, there is no OLM. The car calls for 5K oci for normal service in N America, in Europe and Asia it is 10K. For the first 50K I did the 5K changes to protect the 60K Powertrain warranty, I am in the process of trying an extended oci with used oil analysis at 2.5K. I am currently at about 6K and two used oil analysis can be found in the proper section, I also did a VOA on the oil (Mobil 1 0W20). Under certain driving conditions the ice can be off quite a bit even though the battery only lasts a short time. This is accomplished using a technique called pulse and glide. You accelerate using the ICE up to say 40 MPH then let of the gas to a point where the ICE shuts down and you just coast or "glide" without using the battery or the ICE to a slower speed say 33 MPH and then repeat. I have found deserted stretches of road where I have done a loop (no net change in elevation) of 48 miles with an average of 103 MPG, the engine was probably only running 50-60 % of the distance traveled. For the most part this can only be accomplished around town in a rural setting. On the highway the ICE is on about 99.9 % of the time.
 
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Can you say unsprung weight?
nono.gif


Ed




That was my thoughts initially, but then I read
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Each wheel develops 160bhp - 640bhp in total. The original Mini One develops less than 100bhp with an engine that weighs nearly double the weight of the four electric wheels!




So it's maybe not much of an issue.

Could be resolved with some complexity by having the motors rigidly mounted, and short driveshafts to each wheel (like the inboard mounted brakes on some Jags and Citroens to reduce unsprung weight).
 
Half of the mini engine is still probably around 200 pounds or more. As you know, removing just a few pounds of unspring weight makes a noticable difference. Adding half of the weight of an engine can't be good.

I went to the web site to see if they had mounted them inboard, as to me, that is the only thing that would make sense.

Ed
 
The neat thing about this mini is that the gas engine is so tiny and runs at a fix speed to optimize its fuel efficiency.

Very cool!
 
Quote:


Half of the mini engine is still probably around 200 pounds or more. As you know, removing just a few pounds of unspring weight makes a noticable difference. Adding half of the weight of an engine can't be good.

I went to the web site to see if they had mounted them inboard, as to me, that is the only thing that would make sense.

Ed




If your designing an all out sports car, yes unsprung weight is a factor. But how much does an average tire and wheel weigh now? 35-40 lbs.? And let's not forget all the Mustangs and Camaros that were built with solid rear axles for decades...talk about unsprung weight.
 
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