Horrible mileage and not enough power

[Roshambo]

Well, maybe your TC is slipping? That is the problem I am having right now, so Im just going to swap to a SM465 with a doubler while I am at it.

-Joe

 

[kennyw]

[ QUOTE ]
Well, maybe your TC is slipping? That is the problem I am having right now, so Im just going to swap to a SM465 with a doubler while I am at it.

-Joe

[/ QUOTE ]
He has an SM465, thats why we are talking about the gear splits between 3rd and 4th /forums/images/graemlins/wink.gif

Allan, I think you need to put in a Tach. We both have the same tranny (SM465), axle gear ratio (4.10) but you have 35" tires while I have 33's. So you should be able to go faster in 3rd gear than me at the same RPM. What do you feel your RPM limit is on your motor? 3500-4000 RPM? My small block will run loaded up the mountains at 3500-4000 comfortably.

Gear calulator

With 35" tires, 4.10 gears in 3rd gear:
35mph = 2341 RPM
40mph = 2675 RPM
45mph = 3009 RPM
50mph = 3344 RPM
55mph = 3678 RPM

 

[GMCLegacy]

SM465
L-1-2-3

....4th gear, eh?

 

[mountainexplorer]

This truck, right after we got it in 2001, had 235/85R16's on it (equivilent to a 'rated' 33" tall tire). When I drove it home, the thing felt like it had 4.56 gears, but it only has 4.10's. With 33's, going about 65, it was really rapped out.

I don't have a tach in it, but I know I was at the point I didn't want to rev it up any higher. Also, with the 35's on it, my speedometer isn't exactly dead on either, but at that low a speed, it shouldnt be too far off. Going 65 mph, when I have gone 1 mile, it reads I have gone 9/10 of a mile.

 

[kennyw]

[ QUOTE ]
SM465
L-1-2-3

....4th gear, eh?

[/ QUOTE ]

Ever counted gears pulling a load? /forums/images/graemlins/rotfl.gif Just because they renumbered them for people that didnt know to use second gear to start out unloaded doesnt make it a 3 spd.

L is first
1 is Second
2 is Third
3 is fourth

Very simple /forums/images/graemlins/tongue.gif

 

[kennyw]

[ QUOTE ]
Going 65 mph, when I have gone 1 mile, it reads I have gone 9/10 of a mile.

[/ QUOTE ]

So your approx 10% off... at 60 on your speedo your actually going 66, At 30 you would actually be going 33. Although the unmanned radar boxes they put up to tell people their speed would be better for checking how far off you actually are. Or check your odometer over a 10 or 100 mile stretch. That might help get a better picture of how far off you are.

Also since there is a 10% error in your speedo/odometer there is also an error in your gas mileage calculations. You have to adjust the mileage you pull off of your odometer to actual mileage before using it to figure out your gas mileage.

 

[darkshadow]

i dont know about swiching too fi, it sounds alright but I have met a guy out here and all he dose is works on chevys, in his driveway: 2 blazers, 2 jimmys, 1 sub, 1 p/u,1 1-ton p/u. All this guys dose is swiches fi trucks BACK to carbs, he re orders jets and rods for the economy he wants and puts the hottest hottest spark he can, good hot spark and you don't waste any fuel. Now all this guy dose is this so he is slowly perfecting it and has done quite good at it. he bleeds gmc and loves carbs. I wouls get as hot a spark as you can and find the best carb man you can.


and might i say that is a kick ass truck ( my desktop background) /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif/forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif/forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif/forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif/forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif/forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/bow.gif

i think he about doubled his mialige in his 1/2 ton pu

 

[mountainexplorer]

[ QUOTE ]
Also since there is a 10% error in your speedo/odometer there is also an error in your gas mileage calculations.

[/ QUOTE ]

I kinda figured that would be the case before I calculated, but I figured it would be a close estimate. I haven't really wanted to go back and try to make adjustments. If I actually thought about how to do it, it might not be that hard. I just don't want to think. /forums/images/graemlins/smirk.gif

This would mean I actually went more miles than I recorded... and maybe got a slight bit better mileage I think. But it's still bad.