GM Inside News Forum - View Single Post

jckjds · 09-30-2007, 11:22 AM

I still contend that GM made this engine too large. GM already has the 6.6 for power mongers. The only other purpose of a diesel is to provide good fuel economy. Thus, this engine should have been 3.0-3.5 liters and get class leading (by a large margin) fuel economy. Instead, GM now has two hulking diesels, neither of which will probably wow anyone in the fuel economy department.

GM could have hit a home run by producing a 3.0-3.5 litre diesel with 200 hp and 350-400 lb ft of torque (which is MORE than plenty for the average truck buyer) that gets, say 25-30 mpg combined (i.e. true sedan mileage). Instead, we'll get another powerful diesel (reportedly 300+hp and 500+ lb ft) that will probably get 10-15 percent better mileage than the gas options, which won't be enough, IMO to make people switch from their gas engines (at least not en masse). This new 4.5 will essentially be competing with the 6.6 IMO.

An added benefit of making a 3.0-3.5 diesel would be that GM could have used the same diesel for both cars an trucks (instead of building the 2.9 AND the 4.5), which would have saved engineering and tooling costs.

Oh well.

09-30-2007, 11:22 AM	#12 (permalink)
jckjds 3.0 Liter SIDI V6 Join Date: Sep 2003 Posts: 534	Re: GM to make 94,000 4.5L diesels per year I still contend that GM made this engine too large. GM already has the 6.6 for power mongers. The only other purpose of a diesel is to provide good fuel economy. Thus, this engine should have been 3.0-3.5 liters and get class leading (by a large margin) fuel economy. Instead, GM now has two hulking diesels, neither of which will probably wow anyone in the fuel economy department. GM could have hit a home run by producing a 3.0-3.5 litre diesel with 200 hp and 350-400 lb ft of torque (which is MORE than plenty for the average truck buyer) that gets, say 25-30 mpg combined (i.e. true sedan mileage). Instead, we'll get another powerful diesel (reportedly 300+hp and 500+ lb ft) that will probably get 10-15 percent better mileage than the gas options, which won't be enough, IMO to make people switch from their gas engines (at least not en masse). This new 4.5 will essentially be competing with the 6.6 IMO. An added benefit of making a 3.0-3.5 diesel would be that GM could have used the same diesel for both cars an trucks (instead of building the 2.9 AND the 4.5), which would have saved engineering and tooling costs. Oh well.