VetteJohn

Why is the fuel mileage so much lower on the ZR1 than the base car or 06? Is it just the extra horsepower or is it geared differently (rear end or tranny)?

GX427

Rear gear is the same 3.42 some of the trans gears are different but yeah your running 638hp and it’s a little heavier I know the blower has the bypass valve so it gets better fuel economy and releases boost but it’s a little expected when you have 638hp

GMJim

I've been on several trips with other Vettes LS2 and LS3 and I'm stopping for fuel before them every time. 6th. gear on the MH3 / LS9 is 0.67. the base and most others is 0.50. I'm at about 2100 at 70 MPH and with a 0.50 it would be about 1400 or so if memory serves me. This is where the difference in fuel consumption is.

CrystalRedZ07

Exactly!

passagemaker43

The gearing is definitely a major factor but the effect of the massive low end power generated by the supercharger (and the resulting extra gas mileage loss) as well as the effect on gas mileage efficiency of the necessarily lower compression ratio are also major factors. Among my cars are a 2010 ZR1 and a 2009 track Z06 making an equal amount of horsepower at the upper end but the ZR1 wins the initial punch contest. Granted the gearing difference lets the track Z get about 21 MPG if I behave myself on the highway but around town and, if I am messing around some, that mileage drops to 12 to 13. For comparison the best I get on the highway at the same speeds in the ZR1 is upper teens. Mixed driving drops it to 15 to 16 MPG. Though I do mess with it some, never as much as in the track set up Z (it is just so much more fun) so I really don't know what the mileage would be in the ZR1 with sustained very aggressive driving.
Not to take away all the many advantages the ZR1 offers, gas economy is definitely the big sacrifice. I have toyed with pulling the transmission and changing the 6th gear ratio to something closer to the Z06 since the rate of acceleration after fifth gear hits 180 MPH isn't something I would likely care about in my use of the car. So far I just use a different car for any extended trips. Clearly most people won't even think about gas mileage differences with cars like these but for anyone interested I thought the discussion was worth having anyway

Hope this info helps

captain vette

Going from an Ls3 to a ls9 means stopping at the pump more often although the 200 plus HP always make me smile and forget about all the rest

Sub Driver

Who cares?

chatcher

A 1/4 tank only lasts me 15-20 minutes LOL!!

VetteJohn

Thanks for all the responses. I thought I remembered the rearing was different but wanted to conform it. The MPG isn't an issue for me as all the "upsides" more than makes up for that one negative,