Re: EGR causing wear/polishing of cylinder liners & rings.
I have seen diesel engines dismantled with premature cylinder wear/blowby/oil consumpption because the exhaust gas reintroduced into the cylinder via the EGR has added extra carbon abrasive particulates . This is also measurable on an ongoing basis via engine oil analysis.
"In diesel engines in particular, EGR systems come with serious drawbacks, one of which is a reduction in engine longevity. For example, because the EGR system routes exhaust gas directly back into the cylinder intake without any form of filtration, this exhaust gas contains carbon particulates. And, because these tiny particles are abrasive, the recirculation of this material back into the cylinder increases engine wear. This is so because these carbon particles will blow by the piston rings (causing piston-cylinder-interface wear in the process) and then end up in the crankcase oil, where they will cause further wear throughout the engine simply because their tiny size passes through typical oil filters. This enables them to be recirculated indefinitely (until the next oil change takes place").(source wikipedia)
Ps: if you have verifiable data to the contrary, then Wikipedia, according to policy, will modify/upgrade their info above.
In the interim, I'll go with what I've seen in dismantled engines and ongoing engine oil analysis.
