Why is my Yanmar 3TNV88 in my new Thwaites dumper not as powerful as my old dumper with the same engine in.

For anybody with an older Thwaites 3 tonne dumper who may be wondering why their newer Thwaites dumper with what appears to be the same engine in hasn’t got the same ‘grunt’ here is the answer.

When the emissions regulations for Euro Stage V were implemented in 2019 it brought into scope the smaller engines which had always been exempt and therefore the NOC and PM emissions permitted got tighter. The bar was now lowered to cover engines above 19kW and effectively meant that the Yanmar 3TNV88-XWA2 fitted into the Thwaites 3 Tonne straight and Thwaites 3 Tonne power swivel dumpers  were not ‘dolphin friendly’ as they produced up to 28kW@3000rpm and therefore were in scope. To continue fitting an over 19kW engine would have mean fitting the Yanmar 3TNV88C which is a common rail, electronic engine with DPF after treatment with the associated price tag of over £2k extra just for the engine, let alone the electronics upgrade it would have needed.

To get over this problem Thwaites, along with all the other dumper manufacturers, decided to put an engine in that was below the magic figure of 19kW to avoid the unnecessary expense of going common rail. For Thwaites this meant fitting the Yanmar 3TNV88-BWWA engine which is an 18.1kW engine as opposed to the Yanmar 3TNV88-XWA2 which was nudging 24kW. This de-rated engine is 25% less powerful than its predecessor and hence in comparison will feel like it has less grunt. This is compounded by the fact that they are now hydrostatic as opposed to the old ‘cog swapper’ and therefore you miss out on the direct coupling a gearbox gives you as you always lose a bit of power with a hydraulic system.

As the largest supplier and stockists of Yanmar engines in the UK PES are able to offer both types to replace your Yanmar 3TNV88 engine in your Thwaites dumper, whether it be the ‘full chat’ 3TNV88-XWA2 or the de-rated 3TNV88-BWWA. As many sites now, especially inner-cities, insist on all diesel plant being Stage V emission compliant you need the correct engine with the correct emission label on to comply so it’s essential that you don’t try and ‘cheat’ as they are not interchangeable as they are different engines. If you need an engine for your Thwaites dumper ring the experts at PES who’ll be able to supply the correct Yanmar engine for your application.