Glides like a Brick Wall (Jeep Cherokee, GMC Pick-up)

[Big Dave]

Thought you were talking about my Valkyrie. That critter is so draggy that when you roll off the throttle you think you've driven into a bridge abutment.

My big honkin' truck will take a half mile to coast down. I can't coast that bike 200 yards.

Back on topic.

Did I miss something? I think Don indicated he lives in Michigan. Useless he's a yooper, he drives on roads flat as a pool table for the most part. Cruise control is A-OK in flat country.

Don, like most folks in country dominated by tough winters need two different set ups. A set of stock wheels with the snow tires of choice. My own snow strategy has always been "pizza-cutters." Tall skinny tires with aggressive tread that reach down to find something sorta solid. And another set for July and August.

Despite what Ohio State fans tell you, there are periods of dry weather in Michigan. Those dry periods off Don some relief from high fuel consumption. I'll speak to the Chevy pickup, because I know Chevvies better than Jeeps.

That truck probably has GM 12 bolt axles with a 3.73:1 gear ratio. This is a common and flexible setup that lets his 350 rev up and make a lot of power and burn a lot of gas. IIRC, you can get at least 3.08s and maybe 2.73s for the front and rear twelve bolts. If he has a ten bolt he could even go on down to a 2.56 ratio. A lower fear ratio will reduce his fuel burn at any road speed by reducing the engine frictional HP and forcing the engine to operate at a more open throttle setting. The more the throttle opens, the more efficent his engine becomes. R&P sets can be bought and jeep shops do this gear change thing all the time. a numerically lower ratio will help in winter as it will slow down the small-block's tendency to rev up and bury the truck from wheel spin due to the small-blocks huge torque rise.

An aero treatment - fastback or tonneau and air dam - is worthwhile if Don drives a lot over 40 MPH. If he spends most of his nice weather bouncing down country roads at 30 MPH, then weight reduction is the way to go.

[gaorenst]

Originally Posted by deadman1474

I always wanted to know the same thing. Like my pickup truck with a 5.7 Hemi gets 16-28 But if you were to put a smaller engine in it would it get worst mpg. They offer it in a 6 cylinder and its is suppost geting worst gas millage. But they say thats because the hemi has mds.

Deadma1474,

Are you really getting 28 mpg on the freeway or am I reading this wrong?

Regards,

[red91sit]

Originally Posted by Deadma1474

I always wanted to know the same thing. Like my pickup truck with a 5.7 Hemi gets 16-28 But if you were to put a smaller engine in it would it get worst mpg. They offer it in a 6 cylinder and its is suppost geting worst gas millage. But they say thats because the hemi has mds.

I've noticed this to happen quite often I think a lot of it has to do witht he transmissions. To get the same power output, the smaller engine has to be at higher rpm than the large one, so they usually stick a higher final drive ratio on them.

As far as underpowered vehicles go, my newest aquisition has a whopping 90hp. I was a little concerned about fuel economy since it only has a 3sp automatic, and not much for aerodynamics. My first trip with it was 800 miles of interstate at 70-90 mph. The pedal was nearly to the floor the whole time, and to my amazement, it retured 26 mpg!! A vast improvement to the Merc. with twice the H.P. and roughly equivelant Cda.