Bought a 5.3L 4x4 Tahoe, and I average no more than 12MPG around town. I made a trip down to South Carolina, hauling only myself, and got about 17.5 @ ~75. Is this normal? I know that this thing weighs more than my truck, AND it has an automatic xmission, but I would think it should do a little bit better than it does.
It has 38k miles.... Has great get-up and go compared to several I have driven before taking the loan out on this one. New air filer. Run 93 octane.
I know what a lead foot is. I have babied a full tank around town, and still don't get more than about 12.
How true. Generally, the farther down this list you go, the worse the gas mileage will be:
GU4 Rear axle, 3.08 ratio
GU5 Rear axle, 3.23 ratio
GU6 Rear axle, 3.42 ratio
GT4 Rear axle, 3.73 ratio
GT5 Rear axle, 4.10 ratio
The EPA information on my 2-WD 2004 Silverado truck (4.8L V-8, 4-speed auto, 3.42 axle) says I can expect 17 City and 20 highway.
However, the fine print adds that actual mileage may be between 14 and 20 mpg in the city and between 17 and 23 highway. Over the first year, the truck has averaged 16 mpg, with a low of 15.3 and a high of 19.1.
Why run 93 Octane gas? Not needed unless you used a Power Programmer and reconfigured your Engine to require a 91 Octane or higher. Or your running a Supercharger. Your actually getting less performance from a higher Octane fuel then you would a lower. You need a Higher Octane to keep your Engine from Pinging. Higher Octane makes the fuel burn slower! If your Engine is still stock, (Unless it came stock with a Supercharger!) your just throwing money away. At prices these days, it's just dumb. That's something like $7 per tank of gas on average depending on tank size and difference in price from Regular to Premium Gas. Or around $330 a Year your throwing away if you filled up once a week. Most cars and trucks out there do NOT require Premium Gas.
What is the purpose of the knock sensor? If the engine can run more timing advance, power and fuel mileage go up. Lower octane means spark knock, which means timing retards, power goes down, fuel mileage goes down. Sometimes high test is too much, and the middle grade will work just fine. Me I burn High test, my unscientific recording of fuel mileage tells me I get 2-3 miles per gallon more on high test then on regular, and the seat of my pants gut feeling tells me the truck has more power when I jump on it with high test.
Yeah, it's all stock... it's just appalling that my '95 even back when it was TBI got considerably better milage. Got word from somone to try a tornado. Said it gave him 2-3 mpg better... i dont know if he had a 4wd or not. Thanks!
Have someone else start filling your gas tank. Then you try to guess from tank to tank what type of fuel was put in there when it's down to half a tank or so. See if you really feel a performance Increases and/or your Mileage actually goes up or not! Don't fill the tank yourself. You'll get that placebo effect and think your getting better performance when your not. The Computer does do some Adjustments according to Factory Specs. If you want Performance using Premium Fuel, you need to Re-Configure your Computer. Depending on the year, either a Chip, or a Power Programmer. You'll feel the performance incress, especially when you get used to it and then set your computer back to stock again. If you have a Diesel, you really see a big Increase in HP and Torque.
Using Premium Fuel because you think you'll get better Performance and Mileage is just another myth thats been around for ages. One of many Automotive ones going around. Hell why not ad one of them Strong Magnets to your Fuel line! You've seen those haven't you? Supposedly increases your Gas Mileage and Performance. How about them Tornado's. Ad it to your Intake, supposedly swirls your Incoming Air to give you better Performance. Ya right. What's that one fuel Additive you put under the hood and hook up to the Vacuum line and it ads a little of this Crap to your Intake system to give you better Performance and fuel Mileage. Do you see a theme. There's a lock of suckers out there that want to believe all this crap.
Hey, do you buy your Gas at Union 76, or Chevron or some other Expensive Gas Station, instead of the cheap place because you think the gas is better? Guess what, it's another myth. It all comes from the ground. It's all Refined at the SAME PLACE. It all goes though the same Pipelines. All the trucks fill up at the same place and then some of them dump a little amount of their additive in after. The Higher price your paying is Advertising and bigger profit margin. That's all. Myself, I get the cheapest Regular Unleaded gas in town which happens to be from COSTCO! On my 03 Silverado 5.3L, runs GREAT. The only time I EVER buy Premium fuel is for my Jetski, and that's only because it's been Modified with a Higher Compression head. When it was all stock it ran on Regular.
I'm a nice guy JB so I'll point you to a site and you can grab a bit of education. That way when your lips are flapping you will know what you're talking about. Now I know it's tough, but there are much smarter people out there than you and I. Heck I live in Alberta and there are several refineries nearby so I know the gasoline you and I burn does not come from the same company. Do check out the 'V Power' link on the site.
From the Shell site here...
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Consider the following guidelines when selecting a gasoline for your car: Don't Overlook Octane: Different cars require different levels of octane, which is the measurement of a gasoline's ability to resist engine knock - a rattling or pinging sound that results from uncontrolled combustion in the engine. The right level of octane will prevent engine knock and help ensure optimum performance. To determine the appropriate octane level, be sure to check your car's owner's manual for the manufacturer's recommendation.
The most common levels of octane are 87 (regular), 89 (mid-grade) and 93 (premium). These levels are indicated on each gas pump at the station. Higher-octane gasoline can be helpful particularly for car engines that are experiencing knocking or pinging. However, octane is only one component to consider when shopping for fuel.
Consider Cleaning Capabilities: In the mid 1990s, the US Environmental Protection Agency established minimum standards for cleaning agents that must be added to auto fuel, and most gasolines today contain just that minimum amount. Unfortunately, for some vehicles, this minimum level of detergency can leave carbon deposits on important engine parts over time. Carbon deposits on an engine are similar to the "gunk" that can build up over time inside your oven at home.
This is particularly true of low-detergent gasolines typically sold at discount gasoline stations, grocery stores and wholesale club stores. The deposits that low-detergent gasolines leave behind in some cars can cause hesitation during an engine's initial warm-up phase. Removal and prevention of these deposits may help reduce hesitation. Learn about the benefits of high-detergency gasolines, such as Shell V-Power
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Yeah that cheap place that hasn't changed the filters on his pumps in 2 years, hasn't checked for water in his tanks in even longer.
And don't bother with the expensive engine oil ether, that 79 cent a quart super market stuff is just fine, after all it all comes out of the same hole in the ground.
Since you have an 03 Tahoe, you probably have 16" rims. The standard rear end offered with 16" rims is the 3.42 and the 3.73 is the next step up.
The 3.08 was offered only with 15" rims and the 3.23 is a new creation for the 2005 Silverados with 17" rims.
Ordering trucks with the optional 3.73 axle is a very inexpensive way for a dealer to give trucks with low-powered, 4.3L motors approximately 10% more power than they would have with the standard 3.42 axle ratio. The same principle applies with larger motors, even if the customer doesn't require the extra power. Highway mileage on these higher-ratio trucks will be at least 10% lower than those with the standard ratio.
Combining a 5.3L motor with a 3.73 axle creates a jack rabbit-quick truck. The problem with this setup occurs whenever the truck goes into high gear because the motor will always be running 10% faster than its 3.42 counterpart. If you don't need the extra power, this combination wastes gas.
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