· The recommended gasoline for most GM cars, trucks and SUV’s is 87 octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. In some cases, cold weather starting and performance may be compromised. Your best bet: follow your owner's manual.
· The only time you might need to switch to a higher octane level is if your car’s engine develops a heavy knocking noise when you drive. This happens to a very small percentage of cars.
· Unless your engine is knocking, buying higher octane gasoline is a waste of money too. Premium gas costs 15 to 20 cents per gallon more than regular. That can add up to $100 or more a year in extra costs. Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need.
What are octane ratings?
Octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders. Most gas stations offer three octane grades: regular (usually 87 octane), mid-grade (usually 89 octane) and premium (usually 91 to 93). The ratings must be posted on bright yellow stickers on each gasoline pump.
What's the right octane level for your car?
Check your owner's manual to determine the right octane level for your car. 87 octane is recommended for most GM cars and trucks. However, some cars with high compression engines, like Corvette and certain luxury cars like Cadillac CTS, recommend premium (91 octane or better) or mid-grade gasoline to prevent knocking and ensure their best performance. Again Check The Owner's Manual - most models can be run on regular fuel if the vehicle is not being used under extreme conditions and doesn't exhibit any adverse reactions.
What about Gasoline Additives and Fuel Injector Cleaner?
To provide cleaner air, all gasolines in the United States are now required to contain additives that will help prevent engine and fuel system deposits from forming, allowing your emission control system to work properly. You should not have to add anything to your fuel. However, some gasolines contain only the minimum amount of additive required to meet U.S. Environmental Protection Agency regulations. General Motors recommends that you buy gasolines that are advertised to help keep fuel injectors and intake valves clean. If your vehicle experiences problems due to dirty injectors or valves, try a different brand of gasoline.
Are all Diesel Fuels the same? What fuel is recommended for a Duramax Engine?
In the United States, for best results use Number 2–D diesel fuel year-round (above and below freezing conditions) as oil companies blend Number 2–D fuel to address climate differences. Number 1–D diesel fuel may be used in very cold temperatures (when it stays below 0°F or 18°C); however, it will produce a power and fuel economy loss. Avoid the use of Number 1–D diesel fuel in warm or hot climates. It may result in stalling, poor starting when the engine is hot and may damage the fuel injection system.
Sources:
2002-2004 Cavalier O/M
2004 Corvette O/M
2004 CTS O/M
2004 Duramax Diesel SupplementGM Service Information
www.fueleconomy.gov
Sunday, November 25, 2007
Saturday, November 17, 2007
Out of this World Service
When someone is disappointed or downright mad about a product or service experience, they typically tell everyone they know about it. If the same person has a positive experience, statistically, they tell practically no one.
Well, after years of hearing tons of complaints, I am going against the grain and telling everyone about the Great experience I had today at Saturn of Port Richey.
Although I handle most of my own service work, I just cant justify investing $15000 in a wheel balancer to my wife. So, when needed, I utilize the Saturn dealer's excellent service department.
Yes, I actually practice what I preach and trust GM service facilities with my GM vehicle.
Anyway, I brought the VUE in for a tire rotation and balance, oil change (I had a coupon) and to get a second opinion on a gnarly rattling noise my air conditioning compressor has been making lately. I signed for the services and a $45 diagnostic fee to check the noise and retreated to the waiting room. Ten minutes later, the shop foreman spotted me, remembered my name, and we shared a typcal 'car talk' conversation. He promised to check on the car for me and at that I went to peruse the showroom. After checking out the new models, I walked the used car lot and ended back at the service department where I spotted Pat, the foreman. He agreed that the noise is coming from within the a/c compressor which he said is rather expensive and instead suggested (since the a/c is ice cold) driving it until it gets louder. I also ran a few other questions by him and he gave me a bunch of information and advice I could have gotten no where else. I went back inside, paid the bill and noticed that they didn't charge the diagnostic fee I signed for. When I asked about it they brushed it off and said not to worry about it. I love these guys. Walking outside, my VUE pulled into the service drive washed and vacuumed - even the windshield was cleaned. Like Snickers bars on Halloween, I handed out tips and left a happy man with more money left in my pocket than expected. My expectations had been exceeded in less than an hour.
These guys reinforce my belief that there are good, honest places left on Earth to bring your car and not only get what you pay for, but actually get more than expected. I've purchased my last two vehicles at Saturn of Port Richey and foresee buying there again. They dont sponsor my site, and I drive past 3 other GM dealers to get there, but I get a fair price for my trade, pay a fair price for a car, and the service is so good that I'm tempted to hang up my oil filter wrench for good.
Well, after years of hearing tons of complaints, I am going against the grain and telling everyone about the Great experience I had today at Saturn of Port Richey.
Although I handle most of my own service work, I just cant justify investing $15000 in a wheel balancer to my wife. So, when needed, I utilize the Saturn dealer's excellent service department.
Yes, I actually practice what I preach and trust GM service facilities with my GM vehicle.
Anyway, I brought the VUE in for a tire rotation and balance, oil change (I had a coupon) and to get a second opinion on a gnarly rattling noise my air conditioning compressor has been making lately. I signed for the services and a $45 diagnostic fee to check the noise and retreated to the waiting room. Ten minutes later, the shop foreman spotted me, remembered my name, and we shared a typcal 'car talk' conversation. He promised to check on the car for me and at that I went to peruse the showroom. After checking out the new models, I walked the used car lot and ended back at the service department where I spotted Pat, the foreman. He agreed that the noise is coming from within the a/c compressor which he said is rather expensive and instead suggested (since the a/c is ice cold) driving it until it gets louder. I also ran a few other questions by him and he gave me a bunch of information and advice I could have gotten no where else. I went back inside, paid the bill and noticed that they didn't charge the diagnostic fee I signed for. When I asked about it they brushed it off and said not to worry about it. I love these guys. Walking outside, my VUE pulled into the service drive washed and vacuumed - even the windshield was cleaned. Like Snickers bars on Halloween, I handed out tips and left a happy man with more money left in my pocket than expected. My expectations had been exceeded in less than an hour.
These guys reinforce my belief that there are good, honest places left on Earth to bring your car and not only get what you pay for, but actually get more than expected. I've purchased my last two vehicles at Saturn of Port Richey and foresee buying there again. They dont sponsor my site, and I drive past 3 other GM dealers to get there, but I get a fair price for my trade, pay a fair price for a car, and the service is so good that I'm tempted to hang up my oil filter wrench for good.
Monday, November 12, 2007
Check Engine – yup, it’s there!
All vehicles manufactured with computerized emissions controls are required by law to have an indicator designed to alert the operator of a system malfunction. Hence the Check Engine lamp, Malfunction indicator, idiot light, etc. was born.
At the dealership, “Check Engine light on” was one of the most common complaints that we diagnosed. Questions you should prepare to answer included: how long has the light been on, does it flash or stay on continuously, does the car seem to perform properly (ex poor fuel mileage, bucking, hard to start, etc.), have there been any modifications to the car, and last but not least – when did you last purchase fuel?
I have known of a few customers who received bad gasoline but the primary reason for the question refers to the gas cap.
In my experience, one of the most common causes for check engine light illumination on GM vehicles is the improper installation of the gas cap after refueling. Since gasoline fumes are toxic they are a consideration of the vehicle’s emissions control system. The system is monitored to ensure that no fumes are allowed to escape while the engine is running and/or the ignition on.
Therefore, if a driver fills the tank while the engine is running, or more commonly, does not tighten the cap until it clicks (3 times is my suggestion) there’s a good chance the on-board computer will detect an emissions failure and the check engine lamp will come on.
Most GM owner’s manuals recommend checking the gas cap and considering recent driving conditions, specifically if the vehicle had been driven through standing water or in heavy rain. Extreme weather conditions, and extreme operation can contribute to a check engine light coming on; aside from rain, icy conditions, extreme temperatures, and towing can put additional forces on the vehicle’s powertrain and set the light.
So what’s a responsible owner to do?
First check all the obvious things. Is the gas cap tight? I would remove and reinstall it. Check all the fluid levels and tire pressures. A low tire on a vehicle with all wheel drive could trigger the light. Check the fuses. Beyond that, you need professional help. Some aftermarket parts retailers have diagnosis equipment and will test the computer system for little or no charge.
One more thing you need to know – if the gas cap was loose, one tire nearly flat, etc, the light probably won’t go out immediately. Many “codes” that put the light on are set only after reoccurrence of a failure. Therefore, it takes several “key cycles” (ignition on/off) to clear the code out of the computer and turn the light off. “Soft” codes, like a loose gas cap can usually be cleared by disconnecting the battery for a few minutes. If the light comes right back on once the engine starts, it is likely being triggered by a “hard” code which is a more serious failure and will need to be addressed by the dealer or other competent repair facility. Also, it's OK for the light to come on during the "lamp test" when the ignition is turn on but the engine not running. This is to let you know that the bulb itself is not burnt out - it should go off within a few seconds of the engine starting.
At the dealership, “Check Engine light on” was one of the most common complaints that we diagnosed. Questions you should prepare to answer included: how long has the light been on, does it flash or stay on continuously, does the car seem to perform properly (ex poor fuel mileage, bucking, hard to start, etc.), have there been any modifications to the car, and last but not least – when did you last purchase fuel?
I have known of a few customers who received bad gasoline but the primary reason for the question refers to the gas cap.
In my experience, one of the most common causes for check engine light illumination on GM vehicles is the improper installation of the gas cap after refueling. Since gasoline fumes are toxic they are a consideration of the vehicle’s emissions control system. The system is monitored to ensure that no fumes are allowed to escape while the engine is running and/or the ignition on.
Therefore, if a driver fills the tank while the engine is running, or more commonly, does not tighten the cap until it clicks (3 times is my suggestion) there’s a good chance the on-board computer will detect an emissions failure and the check engine lamp will come on.
Most GM owner’s manuals recommend checking the gas cap and considering recent driving conditions, specifically if the vehicle had been driven through standing water or in heavy rain. Extreme weather conditions, and extreme operation can contribute to a check engine light coming on; aside from rain, icy conditions, extreme temperatures, and towing can put additional forces on the vehicle’s powertrain and set the light.
So what’s a responsible owner to do?
First check all the obvious things. Is the gas cap tight? I would remove and reinstall it. Check all the fluid levels and tire pressures. A low tire on a vehicle with all wheel drive could trigger the light. Check the fuses. Beyond that, you need professional help. Some aftermarket parts retailers have diagnosis equipment and will test the computer system for little or no charge.
One more thing you need to know – if the gas cap was loose, one tire nearly flat, etc, the light probably won’t go out immediately. Many “codes” that put the light on are set only after reoccurrence of a failure. Therefore, it takes several “key cycles” (ignition on/off) to clear the code out of the computer and turn the light off. “Soft” codes, like a loose gas cap can usually be cleared by disconnecting the battery for a few minutes. If the light comes right back on once the engine starts, it is likely being triggered by a “hard” code which is a more serious failure and will need to be addressed by the dealer or other competent repair facility. Also, it's OK for the light to come on during the "lamp test" when the ignition is turn on but the engine not running. This is to let you know that the bulb itself is not burnt out - it should go off within a few seconds of the engine starting.
Saturday, November 3, 2007
Tires
During my career I can recall several complaints from younger GM owners who were very upset that their vehicle would not “peg the speedometer” or that the vehicle would not go over 108 miles per hour.
All were surprised when I would inform them that this condition was probably related to their tires.
Attempting to be a responsible manufacturer, GM engineered the computer that runs the engine to limit the top speed of the vehicle.
Why and how does this make them responsible, you ask?
Well, one of the specifications that tires are rated to is a speed rating. A common tire with and S speed rating is designed to travel up to 112 mph. So to help avoid the unfortunate and sometimes deadly occurrence of a high speed tire failure, GM engineered a governor of sorts that keeps the engine from powering the vehicle over the speed rating of its tires. Aftermarket software can by-pass this feature and on a high performance vehicle, such as Corvette which come with Z rated tires (149 mph+) it becomes a non-issue. Obviously, upgrading the tires changes nothing as far as the computer’s concerned.
There’s a great amount of information stamped or molded into tires but the most important things to know are these: always buy the same size tires, always buy tires with at least the same speed, traction and temperature ratings, check the air pressure and inflate to what the vehicle manufacturer recommends – not what’s stamped on the tire. For maximum comfort and wear you should have your tires rotated every 7500 miles and balanced yearly or whenever you feel a vibration.
Here’s a quick breakdown of what all those numbers and letters on the sidewall mean:
P – Passenger Car Tire.
225 - The width of the Tire from sidewall to sidewall in millimeters.
60 – the Aspect Ratio – the relationship of the tire’s height compared to its width –performance tires usually have a lower ratio – the tires are wide and thin.
R – Indicates a Radial ply tire.
16 – is the size of the opening in the center and the matching size wheel.
The Speed Rating is located in one of two places; either before the R as in SR, VR, etc or after the Load Rating code which is also a serious consideration on trucks and SUV’s that are used to carry heavy loads.
So next time you need tires, P225/60SR16 will mean more to you than just being the tire size.
For more information without sales pressure, check out my website, How Stuff Works from the Links page, or your Owner’s Manual.
Don’t have one? Sign up at mygmlink (Links page) and access one anytime!
All were surprised when I would inform them that this condition was probably related to their tires.
Attempting to be a responsible manufacturer, GM engineered the computer that runs the engine to limit the top speed of the vehicle.
Why and how does this make them responsible, you ask?
Well, one of the specifications that tires are rated to is a speed rating. A common tire with and S speed rating is designed to travel up to 112 mph. So to help avoid the unfortunate and sometimes deadly occurrence of a high speed tire failure, GM engineered a governor of sorts that keeps the engine from powering the vehicle over the speed rating of its tires. Aftermarket software can by-pass this feature and on a high performance vehicle, such as Corvette which come with Z rated tires (149 mph+) it becomes a non-issue. Obviously, upgrading the tires changes nothing as far as the computer’s concerned.
There’s a great amount of information stamped or molded into tires but the most important things to know are these: always buy the same size tires, always buy tires with at least the same speed, traction and temperature ratings, check the air pressure and inflate to what the vehicle manufacturer recommends – not what’s stamped on the tire. For maximum comfort and wear you should have your tires rotated every 7500 miles and balanced yearly or whenever you feel a vibration.
Here’s a quick breakdown of what all those numbers and letters on the sidewall mean:
P – Passenger Car Tire.
225 - The width of the Tire from sidewall to sidewall in millimeters.
60 – the Aspect Ratio – the relationship of the tire’s height compared to its width –performance tires usually have a lower ratio – the tires are wide and thin.
R – Indicates a Radial ply tire.
16 – is the size of the opening in the center and the matching size wheel.
The Speed Rating is located in one of two places; either before the R as in SR, VR, etc or after the Load Rating code which is also a serious consideration on trucks and SUV’s that are used to carry heavy loads.
So next time you need tires, P225/60SR16 will mean more to you than just being the tire size.
For more information without sales pressure, check out my website, How Stuff Works from the Links page, or your Owner’s Manual.
Don’t have one? Sign up at mygmlink (Links page) and access one anytime!
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