Isuzu's latest engine is years ahead of any new emissions requirements.
Isuzu says its new 4HK1 engine is the cleanest medium duty truck motor on the Australian market.
The four cylinder powerplant is years ahead of any new emissions requirements. That’s because it complies with Japan’s ‘Post New Long Term’ standard, which is similar to Euro 6.
This has been achieved without selective catalytic reduction (SCR), which needs AdBlue.
As Isuzu says, operators can show environmentally conscious customers they are using the latest “clean, green” pollution technology.
Speaking of emissions gear, of much more practical benefit to operators is the fact that the emissions system on the alternative redesigned Euro 5, six cylinder, 8 litre 6HK1 engine has changed.
There’s still cooled exhaust gas recirculation (EGR) but no more diesel particulate diffuser (DPD). This is the filter that traps particulate and burns it off either automatically or manually.
Automatic regeneration can happen anywhere from cruising along the freeway, where you wouldn’t notice it, to potentially annoying scenarios such as when you are using the power take off (PTO) function or having to do lots of idling. And once the regeneration starts, you shouldn’t stop it.
These hassles are now eliminated with the new maintenance-free diesel oxidation catalyst (DOC), the same emissions control system used in Isuzu’s 10 litre engine range.
“The 6HK1 With DOC is the only medium-duty engine on the Australian market without a diesel particulate filter or SCR,” Isuzu says.
“The technology is well suited to vocational applications requiring high idle time, high PTO use or frequent stop-start duties.”
That includes council trucks, elevated work platform vehicles and bush fire tankers.
Partly because it no longer needs to inject fuel to burn off particulate build-up, Isuzu adds that the revised 6HK1 DOC should use about 5 per cent less fuel than its predecessor.
By the way, the revised 6HK1 with DOC only applies up to 260hp (191kW). There are higher output versions of the 8 litre 6HK1 in bigger F series Isuzu trucks but they don’t have DOC, instead retaining the DPD.
Incidentally Isuzu says there is no evidence that DPD regeneration near long, dry grass can start a fire.
You can read the full feature on the new Isuzu F series range in the April issue of Owner//Driver.