ORIGINAL: RLSH700


[Another thing that is important to remember is that GM generally sets up their engines and transmissions to use taller gearing than most other manufacturers so this isn't too surprising. Although you may be correct about when they are just cruising it will yield an advantage, the issue at hand is that will do very little to help them with the CAFE standards from what I understand. The CAFE standards are based significantly off of the "official" EPA sticker ratings. If those ratings say it does no better than a V8, it's not going to help them. Will it help the customers who drive them? If what your saying is correct, then yes. The other thing is under current use of technology the forced air-induction systems are not being paired up with a multi-displacement systems, and that has the same basic effect of when not being used at full power it really can yield some significant advantages. Our administrator has mentioned many times about how his in-laws were able to get 30mpg with a 300C, but that does little to help Chrysler with the Government because their system says 25 (or 23 by the new standards). Also I have talked to many owners of the last F-body cars (Firebird and Camaro owners) and many of them have claimed that the old ratings they had up to 28mpg was accurate, so I don't know how much better off a person would be with the forced air induction route anyways. I don't know any one who owns the current Vettes or any other models so I can't testify about those per say. I will admit I don't know enough results of forced air inducted cars to make a judgment call about what mileage they get so someone else will have to add that one.

I believe part of the reason why the LS engines do so well in fuel efficiency besides weight and gearing is the compression ratios. The LS2 had a 10.9 to 1 compression, the LS7 has about a 11.1 to 1 or 11.0 to 1 (depending on the source). The 5.7L Hemi currently has a 9.6 to 1, the 6.1L has a 10.3 to 1 in comparison. The Viper's V10 improved significantly from 19 to 22 (using the new standards) thanks to the VCT, the increased compression (from 9.6 to 1 to 10.2), and the updated TR-6060 from the old T-56 transmission, despite the slight displacement increase. If Chrysler would start to use taller gearing, I think that would really help them out a lot on the 6.1L because it really has short gearing currently, no thanks to the MB built transmission's .83 overdrive, plus it is not a very fuel efficient design to begin with.

I will agree that people will be satisfied with its power, it is just a one upping game is all. We want to one up the Mustang is all. I'm sure you understand that. I look forward to your response as I'm enjoying this conversation as well. I like a challenge(r) especially when the person's points are logical and civil, which you do an excellent job of filling that criteria.