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Discussion Starter #1
I bought a '73 CJ5 w/ a hot 327 Chevy :twisted: in it last week and used my Coly to trailer it 260 miles. My last fill-up I got 12.3 MPG, all town miles, not very much idling time, and drove pretty much like a grandma. Got 23.3 MPG about 3 weeks ago all highway, my best ever. I usually average 16-19 over the last three years. Pulled my Jeep and trailer (around 4500lbs) and got close to 17 MPG. What the crap? How does pulling weight at 24-2500 RPM give me better gas mileage than driving like a grandma around town? My truck runs great and sounds great, but I just don't understand it. :? Oh and I have to replace a blown intake manifold gasket on my Jeep, so that will be fun, lol.
 

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What mods do you have for towing?

As for the mileage thing maybe the hoghway miles towing the torque converter locked up giving better MPG.

Riddler
 

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Ive noticed that once moving, such as on the highway, i can get 22+. but around town i get like 15 on a regular basis. My truck at least i notice it takes A LOT to get it going (gas that is) and until i am upto speed, my MPG's is horrid. not sure if this is the case for everyone, or if it is just me though.
 

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Discussion Starter #4
Well I have all the HP mods listed, and then on my tune it's tuned for towing. I have no trouble with power or anything-I always have get up and go and I had no trouble at all pulling the trailer at 65-68 mph.
 

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If you blew your intake manifold gasket that could cause Havok to your MPG's. I don't know where your leak is exactly but it will kill your bottom end power and your throw your air fuel mix out out whack and or lose air velocity going into the head. It could Lean out your mixture because its past the point where the Mass air flow sensor can help calculate or compensate. Think of the mass air flow sensor as a control device and an air leak in that location essentially bypasses that device. Thats just a educated guess.
 

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Discussion Starter #6
Hold on Supertech, I blew my intake manifold gasket on my Jeep. Sry about that, I kinda jumped back to it. But yeah u're right on that.
 

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What gears do you have? That could be a huge reason that your in town mileage is so, you may have 4.10s in it.

That being said, I've noticed that my truck does tend to get better gas mileage with my motorcycle in the bed.
 

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Discussion Starter #8
3.42's , lol. Only gear they had on the lot on a pickup that I liked.
 

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Sorry about that Luke KS I guess I misread that , I see now what you mean. :shock:
 

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I don't know about Kansas but in VA we have 10% ethonal in the cities and but not in the counties and it makes a little more power and is higher octane but it does not go as far. Is it possible you filled up at some location where they use some blend of ethonal ? That might explain it.
 

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I usually get 17 on the winter blend. I towed a Passat on a dolly and got 17.1 mpg. I think it was because I was only going 60-65 mph instead of 75-80 mph.
 

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rangerbob said:
I usually get 17 on the winter blend. I towed a Passat on a dolly and got 17.1 mpg. I think it was because I was only going 60-65 mph instead of 75-80 mph.
Yeah, I don't go any slower with the bike(s) in the back, so I'm completely mystified by mine.
 

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naskie18 said:
rangerbob said:
I usually get 17 on the winter blend. I towed a Passat on a dolly and got 17.1 mpg. I think it was because I was only going 60-65 mph instead of 75-80 mph.
Yeah, I don't go any slower with the bike(s) in the back, so I'm completely mystified by mine.
Yeah - I'd have gone faster but traffic too. *shrug* Plus I was towing this thing around in the foothills so it was like it was flat-ish like my regular commuting. That's another part of why I was surprised about the mileage.
 

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compare rpo codes from inside glove box to this list

GT4 Rear axle, 3.73 ratio
GT5 Rear axle, 4.10 ratio
GU6 Rear axle, 3.42 ratio
 

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i know its a little late to be giving an explanation on the OP but if he was going thru town, he probably wasn't getting into 3rd or 4th gear. so he was probably going about 40 maybe at a constant 24-2500rpm whereas on the highway he would be going almost twice that speed at the same rpm.
 
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