Gas mileage on my truck.. UPDATE

[Howard]

Originally posted by: WinkOsmosis

Originally posted by: Down4U

Originally posted by: flood
your MPG will also depend on how you drive your car.

I don't drive her aggressively. I may engage the over-drive one or two times if I need to, but otherwise I'm rather conservative.

OH MY GOD. Overdrive is a gear. Not using it is why your mileage is so crappy.

How the hell can people not realize what overdrive is???

Calm yourself. The overdrive is simply a viscous coupler like the torque converter, but it serves as a torque divider.

 

[T2T III]

11 M.P.G. or so isn't so bad - for this time of year in your particular vehicle. Consider the following:

1) Colder temps lead to worse gas mileage. Keep a log of your fill-ups and average the numbers out at the end of the summer. More than likely, your vehicle will average much closer to the 15 M.P.G. figure.

2) Winter fuel blends. The current blends of "winter" fuel that are being sold can rob you of about 2 M.P.G.

 

[Down4U]

Originally posted by: Marlin1975
Why are you using High Octane???

Most (like 90+%) run best using 87 Octane.

I've used 87 octane on various cars, and I honestly don't like the sound of the pistons knocing the way they do with the cheaper gas. It almost sounds like the cylinders are about to seize.

I don't mind paying for the more expensive gas, even if it isn't meant for the type of compression my engine puts out.

 

[Down4U]

Originally posted by: WinkOsmosis

Originally posted by: Down4U

Originally posted by: flood
your MPG will also depend on how you drive your car.

I don't drive her aggressively. I may engage the over-drive one or two times if I need to, but otherwise I'm rather conservative.

OH MY GOD. Overdrive is a gear. Not using it is why your mileage is so crappy.

How the hell can people not realize what overdrive is???

Unlike Mitsubishi's and Toyota's which have a button, typically on the transmission shift to turn on or off the overdrive, my truck simply engages it if I step on the gas hard enough.

I think she burns gas quicker when I engage it constantly, or at least it seems like she does, so I don't mind it disengaged most of the time.

 

[Gillbot]

I was wondering why no one mentioned the fact that he was using 93 octane. It will cause poor performance on a motor that doesn't require it. Most people do not know that it is actually worse for your car to run a higher octane than needed. they just think it's better gas.

Originally posted by: Evadman

Originally posted by: etech
I missed that you are using 93 octane.

You really don't need that high of octane and are just wasting money by using it.

you also get less mileage.

 

[Down4U]

Originally posted by: Gillbot
I was wondering why no one mentioned the fact that he was using 93 octane. It will cause poor performance on a motor that doesn't require it. Most people do not know that it is actually worse for your car to run a higher octane than needed. they just think it's better gas.

Originally posted by: Evadman

Originally posted by: etech
I missed that you are using 93 octane.

You really don't need that high of octane and are just wasting money by using it.

you also get less mileage.

93 octane has to be better than 87, and it has to make some sort of a difference. I'm sure there's less junk on the higher grades, not to necessarily imply that it is necessarily superior gas.

 

[Howard]

Originally posted by: Down4U

Originally posted by: Gillbot
I was wondering why no one mentioned the fact that he was using 93 octane. It will cause poor performance on a motor that doesn't require it. Most people do not know that it is actually worse for your car to run a higher octane than needed. they just think it's better gas.

Originally posted by: Evadman

Originally posted by: etech
I missed that you are using 93 octane.

You really don't need that high of octane and are just wasting money by using it.

you also get less mileage.

93 octane has to be better than 87, and it has to make some sort of a difference. I'm sure there's less junk on the higher grades, not to necessarily imply that it is necessarily superior gas.

The ONLY thing the number means is the nominal percentage composition of the gas - i.e. 87-grade gasoline is 87% octane and the rest is heptane.

 

[Gillbot]

Not really, It's not cleaner or anything like everyone thinks. It actually doesn't burn as easily. A motor needs a few things other than Air and spark to run. The compression actually aids in the combustion process. 87 works best in most cars because they are designed around it. Higher octanes are for performance cars with high compression and the like. As the piston comes up right before the plug fires, it compresses the air and fuel to make it easier to combust. In your vehicle, there isn't enough of this "squeezing" and thus the fuel doesn't ignite as easily and will burn more slowly and unevenly causing fuel to be wasted. My car requires 93 octane since i'm running 10.2:1 compression, any less and the fuel explodes as it's compressed, without the plug firing. This is pinging. ANY reputable mechanic will tell you to run as low of an octane as possible without pinging. This would be 87 for 90% of the cars on the road today. Any higher and the fuel is not burning efficiently in the motor and is being wasted. This can also lead to premature catalitic converter failure as it has to work extra hard burining off the excess fuel.

Originally posted by: Down4U

Originally posted by: Gillbot
I was wondering why no one mentioned the fact that he was using 93 octane. It will cause poor performance on a motor that doesn't require it. Most people do not know that it is actually worse for your car to run a higher octane than needed. they just think it's better gas.

Originally posted by: Evadman

Originally posted by: etech
I missed that you are using 93 octane.

You really don't need that high of octane and are just wasting money by using it.

you also get less mileage.

93 octane has to be better than 87, and it has to make some sort of a difference. I'm sure there's less junk on the higher grades, not to necessarily imply that it is necessarily superior gas.

 

[etech]

The ONLY thing the number means is the nominal percentage composition of the gas - i.e. 87-grade gasoline is 87% octane and the rest is heptane.

Gasoline is made up of many different compounds. Is is most definately not a simple binary mixture of octane and heptane.

The octane rating is a measure of how resistant the mixture is to detonation with pure octane having a rating of 100 though it really isn't even that simple with the different methods of measuring it, motor and research.

The main thing you need to know is - if your car manual says to use 87 octane than you don't need any higher and won't get any benifit out of it.

There are even some exceptions to that but mainly dealing with old cars that have carbon buildup or some cars that can adjust their ignition timing to take advantage of the higher octane.

 

[Down4U]

My car requires 93 octane since i'm running 10.7:1 compression, any less and the fuel explodes as it's compressed, without the plug firing. This is pinging. ANY reputable mechanic will tell you to run as low of an octane as possible without pinging. This would be 87 for 90% of the cars on the road today. Any higher and the fuel is not burning efficiently in the motor and is being wasted.

Is pinging when the engine sounds like it's about to give in when it's straining? You know.. When going up a steep hill and it needs to work a little harder to push out some power? I know the difference between 87 and maybe 91 is considerable. My ex used to drive a '91 Ford Escort. She would always put the cheaper gas and always used to make that noise that sounded like the pistons were getting screwed up. As soon as I told her to put 93 octane gas in, the noise stopped.

I don't know.. Maybe there was something else wrong with her car.

 

[Eli]

Originally posted by: Down4U

Originally posted by: Gillbot
I was wondering why no one mentioned the fact that he was using 93 octane. It will cause poor performance on a motor that doesn't require it. Most people do not know that it is actually worse for your car to run a higher octane than needed. they just think it's better gas.

Originally posted by: Evadman

Originally posted by: etech
I missed that you are using 93 octane.

You really don't need that high of octane and are just wasting money by using it.

you also get less mileage.

93 octane has to be better than 87, and it has to make some sort of a difference. I'm sure there's less junk on the higher grades, not to necessarily imply that it is necessarily superior gas.

As others have said, this is absolutely incorrect. It amazes me that people (still?) believe that Octane rating has something to do with the quality of the fuel.

Unless your engine really does ping on 87 octane(in which case, you probably have another problem.. severe carbon buildup, perhaps), you are wasting money, fuel economy, and performance by using Premium.

 

[Gillbot]

i've heard it sounds like "higher pitched" knocking but i run what my manual says and have not heard a motor ping.

 

[Down4U]

Originally posted by: Eli

Originally posted by: Down4U

Originally posted by: Gillbot
I was wondering why no one mentioned the fact that he was using 93 octane. It will cause poor performance on a motor that doesn't require it. Most people do not know that it is actually worse for your car to run a higher octane than needed. they just think it's better gas.

Originally posted by: Evadman

Originally posted by: etech
I missed that you are using 93 octane.

You really don't need that high of octane and are just wasting money by using it.

you also get less mileage.

93 octane has to be better than 87, and it has to make some sort of a difference. I'm sure there's less junk on the higher grades, not to necessarily imply that it is necessarily superior gas.

As others have said, this is absolutely incorrect. It amazes me that people (still?) believe that Octane rating has something to do with the quality of the fuel.

Unless your engine really does ping on 87 octane(in which case, you probably have another problem.. severe carbon buildup, perhaps), you are wasting money, fuel economy, and performance by using Premium.

How would I rectify a carbon build-up problem if that were the case?

 

[Down4U]

Originally posted by: Gillbot
i've heard it sounds like "higher pitched" knocking but i run what my manual says and have not heard a motor ping.

I know what you're talking about. I still do hear it, but not as severe as I've heard it with other cars using the cheaper gas. It sounds like a "healthy" ping if you may.

 

[Eli]

Originally posted by: Down4U

My car requires 93 octane since i'm running 10.7:1 compression, any less and the fuel explodes as it's compressed, without the plug firing. This is pinging. ANY reputable mechanic will tell you to run as low of an octane as possible without pinging. This would be 87 for 90% of the cars on the road today. Any higher and the fuel is not burning efficiently in the motor and is being wasted.

Is pinging when the engine sounds like it's about to give in when it's straining? You know.. When going up a steep hill and it needs to work a little harder to push out some power? I know the difference between 87 and maybe 91 is considerable. My ex used to drive a '91 Ford Escort. She would always put the cheaper gas and always used to make that noise that sounded like the pistons were getting screwed up. As soon as I told her to put 93 octane gas in, the noise stopped.

I don't know.. Maybe there was something else wrong with her car.

Pinging is just that. Its a slightly dull, slightly metallic "thud", or "ping" comming from the engine bay.. It can be almost machine-gun like when it's really bad.

Straining is when an engine is most likely to ping, but what you're describing doesen't sound like pinging.

By the way; almost all newer cars have a ping sensor that retards timing to stop the pinging if it's detected, which results in slightly less fuel economy.

 

[Down4U]

Originally posted by: Gillbot
but i run what my manual says and have not heard a motor ping.

I'm not exactly sure if you ought to trust what the car maker suggests you should use for gas, especially if your engine has some considerable mileage on it. After all, car makers do want you to come back for repairs.

 

[rahvin]

Originally posted by: Down4U

Originally posted by: Eli

Originally posted by: Down4U

Originally posted by: Gillbot
I was wondering why no one mentioned the fact that he was using 93 octane. It will cause poor performance on a motor that doesn't require it. Most people do not know that it is actually worse for your car to run a higher octane than needed. they just think it's better gas.

Originally posted by: Evadman

Originally posted by: etech
I missed that you are using 93 octane.

You really don't need that high of octane and are just wasting money by using it.

you also get less mileage.

93 octane has to be better than 87, and it has to make some sort of a difference. I'm sure there's less junk on the higher grades, not to necessarily imply that it is necessarily superior gas.

As others have said, this is absolutely incorrect. It amazes me that people (still?) believe that Octane rating has something to do with the quality of the fuel.

Unless your engine really does ping on 87 octane(in which case, you probably have another problem.. severe carbon buildup, perhaps), you are wasting money, fuel economy, and performance by using Premium.

How would I rectify a carbon build-up problem if that were the case?

Break down and clean the entire block and heads and rebuild it. If you are pinging use the higher octane to avoid it unless you plan to keep the car for 10 years. Anyone that buys above the manufacturers recommendations in octane without a VERY good reason is an idiot.

 

[Eli]

Originally posted by: Down4U

Originally posted by: Eli

Originally posted by: Down4U

Originally posted by: Gillbot
I was wondering why no one mentioned the fact that he was using 93 octane. It will cause poor performance on a motor that doesn't require it. Most people do not know that it is actually worse for your car to run a higher octane than needed. they just think it's better gas.

Originally posted by: Evadman

Originally posted by: etech
I missed that you are using 93 octane.

You really don't need that high of octane and are just wasting money by using it.

you also get less mileage.

93 octane has to be better than 87, and it has to make some sort of a difference. I'm sure there's less junk on the higher grades, not to necessarily imply that it is necessarily superior gas.

As others have said, this is absolutely incorrect. It amazes me that people (still?) believe that Octane rating has something to do with the quality of the fuel.

Unless your engine really does ping on 87 octane(in which case, you probably have another problem.. severe carbon buildup, perhaps), you are wasting money, fuel economy, and performance by using Premium.

How would I rectify a carbon build-up problem if that were the case?

The heads would need to be removed so you could gain access to the combustion chambers to be cleaned.

When was the last time you changed your sparkplugs? Were they fouled black with carbon, or were they the healthy tanish color with no deposits?

At 113k miles, you're in the middle life of your engine. It should have plenty of life left.

 

[Gillbot]

i dont see how high mileage would cause pinging, it should cause less due to blow by not allowing full compression. and yes, i do trust the automaker. my ford aspire has over 300k on the clock and still runs fine on good old cheap 87 octane

Originally posted by: Down4U

Originally posted by: Gillbot
but i run what my manual says and have not heard a motor ping.

I'm not exactly sure if you ought to trust what the car maker suggests you should use for gas, especially if your engine has some considerable mileage on it. After all, car makers do want you to come back for repairs.

 

[Down4U]

Originally posted by: rahvin

Break down and clean the entire block and heads and rebuild it. If you are pinging use the higher octane to avoid it unless you plan to keep the car for 10 years. Anyone that buys above the manufacturers recommendations in octane without a VERY good reason is an idiot.

Well thank you for calling me an idiot by the way.

My manual does suggest 87 octane for my truck. I do find it funny that people who opt for putting the cheaper gas in their tanks always find themselves leaving their cars at the shop for repairs more often. Don't know, maybe general ignorant observation on my part.

 

[Down4U]

Originally posted by: Eli

The heads would need to be removed so you could gain access to the combustion chambers to be cleaned.

When was the last time you changed your sparkplugs? Were they fouled black with carbon, or were they the healthy tanish color with no deposits?

At 113k miles, you're in the middle life of your engine. It should have plenty of life left.

Ahh I don't know. When I more or less know she needs a tune up (rougher idling than usual, less engine response, etc), then I take her to the shop and let them do it.

I'm sure she has a long time to go. She still runs like new. I just want to keep her running that way, like new.

 

[Eli]

Originally posted by: Gillbot
i dont see how high mileage would cause pinging, it should cause less due to blow by not allowing full compression. and yes, i do trust the automaker. my ford aspire has over 300k on the clock and still runs fine on good old cheap 87 octane

Originally posted by: Down4U

Originally posted by: Gillbot
but i run what my manual says and have not heard a motor ping.

I'm not exactly sure if you ought to trust what the car maker suggests you should use for gas, especially if your engine has some considerable mileage on it. After all, car makers do want you to come back for repairs.

It indeed can cause pinging... carbon buildup in the combustion chamber can increase the compression ratio. It can also cause pinging if there is a hotspot in the carbon buildup igniting the fuel/air before the plug does.

Again.. 113k, while significant.. does not mean your engine is on it's death bed. After an engine is broken in, it enters a period of long life and very little wear(assuming proper maintenance). Assuming things aren't worn out(in which case your Jeep would also double as a mosquito fogger), I bet your cylinders are within 5% of spec.

 

[Down4U]

Originally posted by: Gillbot
i dont see how high mileage would cause pinging, it should cause less due to blow by not allowing full compression. and yes, i do trust the automaker. my ford aspire has over 300k on the clock and still runs fine on good old cheap 87 octane

Well good for you.

 

[Eli]

Originally posted by: Down4U

Originally posted by: rahvin

Break down and clean the entire block and heads and rebuild it. If you are pinging use the higher octane to avoid it unless you plan to keep the car for 10 years. Anyone that buys above the manufacturers recommendations in octane without a VERY good reason is an idiot.

Well thank you for calling me an idiot by the way.

My manual does suggest 87 octane for my truck. I do find it funny that people who opt for putting the cheaper gas in their tanks always find themselves leaving their cars at the shop for repairs more often. Don't know, maybe general ignorant observation on my part.

LOL! Where on earth did you come up with that conclusion? It's totally wacky, lol.

Again.. you are using cheap in the wrong way. Just because the gasoline is cheaper does not mean that it is of lesser quality. Infact, it is the same gasoline - it just has different.. or more.. additives in it that increase octane rating. The Octane rating is simply a (rather non-scientific)measure of the fuels ability to resist spontaneous ignition.. Nothing more, nothing less.

Fortunately, most states regulate gasoline quality. You have nothing to worry about by buying the cheapest fuel you can find.

Pinging is a pretty distinct sound. Once you hear it, you'll know.. since you haven't heard it, I doubt you're experiencing it.. although, it is funny how different people percieve different sounds. Fill it up with 87 and listen carefully next time you're driving.

I just want to reiterate that the fuel you use has absolutely nothing to do with the longevity of your engine.

That is determined by your maintenance habbits and schedules, amongst other things. You could use 5$/gallon 110 Octane Racing Fuel and it would not matter if you never changed your oil and filters.

 

[Down4U]

Originally posted by: Eli


LOL! Where on earth did you come up with that conclusion? It's totally wacky, lol.

Again.. you are using cheap in the wrong way. Just because the gasoline is cheaper does not mean that it is of lesser quality. Infact, it is the same gasoline - it just has different.. or more.. additives in it that increase octane rating. The Octane rating is simply a measure of the fuels ability to resist spontaneous ignition.. Nothing more, nothing less.

Fortunately, most states regulate gasoline quality. You have nothing to worry about by buying the cheapest fuel you can find.

Pinging is a pretty distinct sound. Once you hear it, you'll know.. since you haven't heard it, I doubt your experiencing it.. although, it is funny how different people percieve different sounds. Fill it up with 87 and listen carefully next time you're driving.

LOL I know, I know. I'm sure people find themselves having to leave their cars at the shop often for all kinds of reasons, and I'm sure cheaper gas isn't likely one of them.

I think I'll try that with one of my pop's cars. I'm not sure I want to experiment with a truck that cost me eight grand just a year ago.