Axle Ratio

I am buying a new 2005 Trailblazer. There are 2 to choose from that have all the options I want. The only difference is the axle ratio. One has the 3.42 the other the 3.73. I will be doing some trailering but the weight is only around 2000 lb so I think that either would be OK. Does anyone know what the true impact on MPG is between the 2 options?

Thanks!!

Very little mileage difference, it will pull the trailer better. I pull 3500# with a 3.42, very easy, no strain.

Thanks, I'm glad to hear that becuase the one with the 3.42 ratio turned out to be a demo with 5000 miles on it. I will go and close on the 3.73 latter on today!

I have the 3.73s, and my mileage is now what the sticker says it should be. I have only a K&N drop-in and an Airaid TBS, but I run synthetic oils and lubes all the way around. I also two 2 boats, 3400 and 3900lbs dry with absolutely no problems.

I have the 3.73s, and my mileage is now what the sticker says it should be. I have only a K&N drop-in and an Airaid TBS, but I run synthetic oils and lubes all the way around. I also two 2 boats, 3400 and 3900lbs dry with absolutely no problems.

Thanks,
I'm on my 2nd tank and averagering 15.5 doing mostly rural driving (3 to 5 miles between stop signs and 55 mph). Think I'll get the K&N soon as I can. Excuse my ignorance but what is an Airaid TBS?

Airaid Throttle Body Spacer, it spins the air as in enters the intake manifold, right past the throttle body. They claim (and in my case work) that you get 1-2mpg better. I got much better mileage with the K&N, about 3-4mpg better with this combo on the hwy.

I have one, but please do not get personal on if they actually work or not. When I was looking at getting one, the controversy is huge. Look at their website and look at the reports and see if you think it will work or not. It is really up to you, as some people like me have them and love them, while others classify them with the Turbonator as crap and the debates that I have been involved in were pretty heated, so decide for yourself.