In terms of car model regeneration, why engine model still elected to carried over from previous car model generation?

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theriusDR3
theriusDR3
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Joined: Sat Jan 09, 2016 8:04 am
Location: Pontianak, Indonesia

In terms of car model regeneration, why engine model still elected to carried over from previous car model generation?

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In Formula 1 auto racing the engine model can be changed every year even every season while in reality every road car models still carry-over the engine model generation from previous generation in terms of regeneration.

Your thoughts?

theriusDR3
theriusDR3
8
Joined: Sat Jan 09, 2016 8:04 am
Location: Pontianak, Indonesia

Re: In terms of car model regeneration, why engine model still elected to carried over from previous car model generatio

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Example Honda, they change the engine model generation into EarthDreams GDI even TGDI DOHC for a new generation of Honda cars

And also Mitsubishi recently revealed the Eclipse Cross SUV car with an all-new MIVEC 1.5 inline-4 TGDI engine

Greg Locock
Greg Locock
216
Joined: Fri Jun 29, 2012 11:48 pm

Re: In terms of car model regeneration, why engine model still elected to carried over from previous car model generatio

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A rule of thumb is that in complexity we have three systems in a car. Body. Engine. Transmission. The rule of thumb is that you only introduce one new one of these at a time, if possible. We have a discipline called program size, and the amount of change in each of these is multiplied together to give you an idea of how long it'll take to develop. New engine*new transmission*new body =3*3*3=27, then divide that by some number for you organisation's development speed, 3 being typical then add a year, because. Hence 27/3+1=10 years from scratch for an all new vehicle (say Prius), or two years to put a new engine in an old car with the old trans (3*1*1/3)+1. Or to put an updated engine and gearbox into an existing shell, say 2*2*1/3+1= 2 years

These timings aren't rigorous, but they are robust. The multiplicative effect means that big changes to all three systems at the same time are not encouraged. Small teams working on low production volume vehicles can easily beat these times.