I plan to replace my cars before they reach mega miles . So dont worry myself about valve clearances , or indeed replacing an aging HV battery.
But those who will be running very high mileage, or eventually elderly , mk4's can take some comfort from modern high precision engineering standards. and quality materials.
IMO opinion older cars needed valve clearances checked and adjusted relatively frequently due to inferior quality metals being 'hammered' flat or valve seats being eroded etc. Much less of a problem these days, especially with Hondas engineering quality.Also bear in mind that not only does the hybrids ICE typically run at a constant and relatively unstressed speed ,its not even running at all for a proportion of the cars total miles/kilometers.
I accept that eventually the need to replace a very expensive HV battery might be the tipping point that makes an old mk4 beyond economic repair and destined for the scrap yard. But even conventional cars the vast majority end up being scrapped because they need major mechanical repairs, rust or simply use too much fuel and relatively unsafe by modern standards. A sad end for what the owner regards as a 'perfectly good' car. But when did you last see a Cortina being driven?
New replacement EV and hybrid HV batteries are outrageously expensive at present, partly because you are largely dependent on OE equipment and main dealer prices. But I think there are already a few independent specialists able to renovate and rejuvenate EV batteries, and even rebuild them, replacing individual cells ,perhaps with more advanced improved versions. These specialist may increase in number the future if the demand is there from owners of older EV's and hybrids.
And those cars scrapped because even a renovated battery is not economically viable will add to the pool of other used spare parts available.
