bubba33

The blazer did come in 2wd also. I had a 79 that i put a whole new body on it except for the cab.350 with a mild cam duals no cats and got about 16-17 hwy . It was a 4x4 full time and i put lock outs in it. As far as the weight I doubt a pick up sb is much lighter, the top on the blazers are not really light. I doubt many trucks with a 350 in it are going to get 21 and over mpg on the hwy.21.7 mpg 26 gallon tank = 564 miles for tank.I for one seriously doubt that.

Magikal

Being from North Idaho I know all about the extremes of summer to winter (6-8 inches of snow this weekend and subzero temperatures beginning next week is forcasted) and the only thing common around here for gas is to occasionally (I usually do once a month, some do more often) add a bottle of methanol or isopropyl treatment to the fuel tank. Reason is for water that tends to accumulate inside the gas tank...metal tanks condense water inside, plastic ones....i don't know but it seems to help still....

I never really heard of any gas from the pump straight that has a seasonal mix....

jwruss

Actually the oil companiesw do mix a more volitile gas for colder climates in the fall and winter months. Not sure exactly what is different.

mattsblacktruck

the gas has been switched since the begening of november to the winter blend for the detoit area as for the rest im not sure

Magikal

Ok. Here is an update on my Silverado. I forgot to mention in my original post that when I purchased this truck it had been garaged for the last 2 years w/ very little use (according to the guy I bought it from) and now after putting a couple thousand miles on it, it seems to be getting better mileage now. I cannot get an accurate reading right now though cause we are getting pounded w/ snow (60+ inches in less than3 weeks) so I have been in 4x4 a lot of the time as well as lots of time idling/warm-up...but there is definitely an improvement in MPG since I posted this originally. I lied also when I stated that the plugs/wires were new. I was told that but after further inspection (while I had to replace a faulty thermostat) I noticed that one plug wire differed from the rest. Sure sign to me that it needs new plugs/wires.

I will post back in a few weeks w/ an update again...Thanx again all!!

therewolf

If you do a LOT of highway driving, and mileage is a major concern, AND you aren't concerned about low-end torque, 342 gears may be the answer. They were for me, but my Silverado(04 Crewcab,8ft bed,2500HD-4x4-6.0-and 18MPG)does a lot of highway driving. It costs 1500$ to 2000$ to do it right, so it's not something you should consider lightly.
IMO, all factors taken into consideration, you're not doing too badly right now, see what the new plugs and wires brings you.

Magikal

Sorry but it is quite the opposite, not a lot of highway driving. Mostly just local stuff (>50mi) and ...well...this is North Idaho and being buried in snow/mud/?? is quite common so torque is nice to have around. I won't be changing gearing. I am not really disturbed much by the mileage, I just thought it would be better. Where it is now is more like what I thought it would be...As far as plugs and wires....won't be this week or next either probably. I don't have an accessible shop to use and it is quite miserable outside right now. I shoveled 220 cubic yards of snow off parents cabin yesterday and it is snowing as I type...(8-10 inches more by tomorrow) so standing in the driveway changing plugs and wires isn't gonna happen unless it is absolutely necessary....I suspect that the gearing I have in this truck are 3.72's???

Magikal

Ok all...it finally quit snowing and warmed up enough so that I could give this thing a tune up. I honestly believe that the plugs and wires are the originals....definitely in need of replacement. The wires were the worst...I had to use pliers to remove EVERY one of them from the plugs. More like destroy, none of them came off in a full piece...

Power increase was good (wasn't bad before but now it is hard not to spin the tires a little at each start)

As far as MPG, I haven't driven it enough to know yet. Are there any decent coil upgrades for this? I was surprised to see a coil seperate from the distributor, making me wonder if a 50,000 volt HEI would be good here? I ask only because with older chevy trucks this has always been the biggest improvement I could make.

therewolf

A high quality aftermarket coil sounds like a good plan.

Sounds like you've got 373 gears, a strong combo for power and economy.

I'm probably not the only one who's curious, so let us know what your MPG is.

Best of luck.

ukrkoz

http://www.bankrate.com/brm/news/car...mileage_a1.asp

http://www.eia.doe.gov/emeu/steo/pub/special/oxy2.html

A Primer on Gasoline Blending
Gasoline is composed of many different hydrocarbons. Crude oil enters a refinery, and is processed through various units before being blended into gasoline. A refinery may have a fluid catalytic cracker (FCC), an alkylate unit, and a reformer, each of which produces gasoline blending components. Alkylate gasoline, for example, is valuable because it has a very high octane, and can be used to produce high-octane (and higher value) blends. Light straight run gasoline is the least processed stream. It is cheap to produce, but it has a low octane. The person specifying the gasoline blends has to mix all of the components together to meet the product specifications.
There are two very important (although not the only) specifications that need to be met for each gasoline blend. The gasoline needs to have the proper octane, and it needs to have the proper Reid vapor pressure, or RVP. While the octane of a particular grade is constant throughout the year, the RVP spec changes as cooler weather sets in.
The RVP is the vapor pressure of the gasoline blend when the temperature is 100 degrees F. Normal atmospheric pressure varies, but is usually around 14.7 lbs per square inch (psi). Atmospheric pressure is caused by the weight of the air over our heads. If a liquid has a vapor pressure of greater than local atmospheric pressure, that liquid boils. For example, when you heat a pot of water, the vapor pressure increases until it reaches atmospheric pressure. At that point, the water begins to boil.
In the summer, when temperatures can exceed 100 degrees F in many locations, it is important that the RVP of gasoline is well below 14.7. Otherwise, it can pressure up your gas tanks and gas cans, and it can boil in open containers. Gas that is boiled off ends up in the atmosphere, and contributes to air pollution. Therefore, the EPA has declared that summer gasoline blends may not exceed 7.8 psi in some locations, and 9.0 psi in others.
A typical summer gasoline blend might consist of 40% FCC gas, 25% straight run gas, 15% alkylate, 18% reformate, and 2% butane. The RVP of the gasoline blend depends on how much of each component is in the blend, and what the RVP is of each component. Butane is a relatively inexpensive ingredient in gasoline, but it has the highest vapor pressure at around 52 psi.
In a gasoline blend, each component contributes a fraction to the overall RVP. In the case of butane, if there is 10% butane in the blend, it will contribute around 5.2 psi (10% of 52 psi) to the overall blend. (In reality, it is slightly more complicated than this, because some components interact with each other which can affect the expected RVP). This means that in the summer, the butane fraction must be very low in the gasoline, or the overall RVP of the blend will be too high. That is the primary difference between winter and summer gasoline blends.

Why Prices Fall in the Fall
Winter gasoline blends are phased in as the weather gets cooler. September 15th is the date of the first increase in RVP, and in some areas the allowed RVP eventually increases to 15 psi. This has two implications for gasoline prices every fall. First, as noted, butane is a cheaper blending component than most of the other ingredients. That makes fall and winter gasoline cheaper to produce. But butane is also abundant, so that means that gasoline supplies effectively increase as the RVP requirement increases. Not only that, but this all takes place after summer driving season, when demand typically falls off.
These factors normally combine each year to reduce gasoline prices in the fall (even in non-election years). The RVP is stepped back down to summer levels starting in the spring, and this usually causes prices to increase. But lest you think of buying cheap winter gasoline and storing it until spring or summer, remember that it will pressure up as the weather heats up, and the contained butane will start to vaporize out of the mix.
And that's why gasoline prices generally fall back in the fall, and spring forward in the spring.


WHY DOES IT ALL SOUND LIKE ANOTHER CONSPIRACY PROOF TO ME?