Gas....

[ahodges487]

Bought a 2007 CX-7 on Sunday. What a blast to drive! One question ....will it hurt the car in any way to use regular gas instead of premium? I saw on spec sheet for the '08 that using anything other than 91 octane will impede performance. Is that it or can damage be done?

[offset_98]

I think 2008 m.y. you can use something other than 91.

[jeg0024]

I think 2008 m.y. you can use something other than 91.

93?

[Mazda3]

The 2008 models have mechanical changes to allow the use of 87 octane. Do not use 87 octane in the 2007 model unless it is an emergency.

[koala]

If you're wanting to run a lower octane fuel for the savings, just buy a vehicle that doesn't require 91... ;)

Almost all OBDII cars are designed to run on 87 in an emergency, but beyond this, there is no good reason to do so if your car says it wants 91.

[HeavyH20]

Let's say you drove 15,000 miles in a year at 20 mpg (I wish) for 750 gallons. If you assume a generous 35 cent per gallon hike over regular (here it is 20 cents), that works out to be $262.50 per year. And with that, you will get less performance and mileage which will even reduce the actual cost delta even more. Seems like a waste to run regular. Where I am, the operating delta would only be $150 per year. So, premium all the way. Just say no to regular. Might as well enjoy the better gas which usually includes other performance enhancing qualities like cleaners, etc.

[Mazdaspeedgirl]

Let's say you drove 15,000 miles in a year at 20 mpg (I wish) for 750 gallons. If you assume a generous 35 cent per gallon hike over regular (here it is 20 cents), that works out to be $262.50 per year. And with that, you will get less performance and mileage which will even reduce the actual cost delta even more. Seems like a waste to run regular. Where I am, the operating delta would only be $150 per year. So, premium all the way. Just say no to regular. Might as well enjoy the better gas which usually includes other performance enhancing qualities like cleaners, etc.

I like the way this guy thinks. HERE HERE!! (drinks)

[ahodges487]

Let's say you drove 15,000 miles in a year at 20 mpg (I wish) for 750 gallons. If you assume a generous 35 cent per gallon hike over regular (here it is 20 cents), that works out to be $262.50 per year. And with that, you will get less performance and mileage which will even reduce the actual cost delta even more. Seems like a waste to run regular. Where I am, the operating delta would only be $150 per year. So, premium all the way. Just say no to regular. Might as well enjoy the better gas which usually includes other performance enhancing qualities like cleaners, etc.


I tend to agree Heavy H2O...I guess I wanted someone to verify my hunch. Thanks to all for the input!

[BostonAmy]

This situation actually happened to me this week. I went to the local gas station which is full service. I told the attendant to fill it with premium (93 Octane.) I rolled up my window and was chatting with my passanger. When I heard the nozzle click I looked behind me to see the total and what do you know.....he put in 87 Octane!!! I didn't want to cause a scene especially not knowing the effects it would have, if any. So I paid him and drove off... WOW what a SIGNIFICANT difference in loss of power!!! Beware....It's my own fault for not paying attention to which octance he put in my car, but I will never use less than 91 ever again!

[HeavyH20]

I keep a bottle of octane boost in the back storage just in case regular is all that is available. :)

Some places have even had 90 octane as the highest available grade. You never know when you will get stuck with the low grade stuff.


I like the way this guy thinks. HERE HERE!! (drinks)

Sometimes I think, and other times it is an utterly random, incoherent rambling that is produced ;)

[Mazda3]

This situation actually happened to me this week. I went to the local gas station which is full service. I told the attendant to fill it with premium (93 Octane.) I rolled up my window and was chatting with my passanger. When I heard the nozzle click I looked behind me to see the total and what do you know.....he put in 87 Octane!!! I didn't want to cause a scene especially not knowing the effects it would have, if any. So I paid him and drove off... WOW what a SIGNIFICANT difference in loss of power!!! Beware....It's my own fault for not paying attention to which octance he put in my car, but I will never use less than 91 ever again!

In the 2007 model it is more than a loss of power. The PCM goes into "limp" mode. Basically makes no power above 4500 RPM.

[Mazdaspeedgirl]

This situation actually happened to me this week. I went to the local gas station which is full service. I told the attendant to fill it with premium (93 Octane.) I rolled up my window and was chatting with my passanger. When I heard the nozzle click I looked behind me to see the total and what do you know.....he put in 87 Octane!!! I didn't want to cause a scene especially not knowing the effects it would have, if any. So I paid him and drove off... WOW what a SIGNIFICANT difference in loss of power!!! Beware....It's my own fault for not paying attention to which octance he put in my car, but I will never use less than 91 ever again!

Well you are kinder than I am. It may not have gotten me much, but I would have a chat with the station manager. (chair)

[Mazdaspeedgirl]

I keep a bottle of octane boost in the back storage just in case regular is all that is available. :)

Some places have even had 90 octane as the highest available grade. You never know when you will get stuck with the low grade stuff.



Sometimes I think, and other times it is an utterly random, incoherent rambling that is produced ;) Well kudos to you, for variety is the Spice of Life! :D

[koala]

I keep a bottle of octane boost in the back storage just in case regular is all that is available. :)

Some places have even had 90 octane as the highest available grade. You never know when you will get stuck with the low grade stuff.



Sometimes I think, and other times it is an utterly random, incoherent rambling that is produced ;)

You know how much octane booster you actually need to raise the rating of gas?

Might as well not even bother... octane boosters are just pure marketing.

[UpNorth]

I think i heard my cue - thanks Heavy H2o. I live in a state where the highest octane you can ever get is 90. (Discovered that after my purchase. Never had cause to check before.)

If I could I would put in 91 or higher, but I can report that the 90 still makes for some very fun driving. I have had no problems with adequate acceleration or performance on some simply dazzling mountain roads.

So if you are forced to swallow some 90, I wouldn't worry too much about needing to use an octane booster. Of course the 90 may work for me because it is generally cool here.

[koala]

I think i heard my cue - thanks Heavy H2o. I live in a state where the highest octane you can ever get is 90. (Discovered that after my purchase. Never had cause to check before.)

If I could I would put in 91 or higher, but I can report that the 90 still makes for some very fun driving. I have had no problems with adequate acceleration or performance on some simply dazzling mountain roads.

So if you are forced to swallow some 90, I wouldn't worry too much about needing to use an octane booster. Of course the 90 may work for me because it is generally cool here.

Do you live/drive at high elevations? octane becomes less and less important the higher above sea level you are... so it may not be the end of the world.

[UpNorth]

Do you live/drive at high elevations? octane becomes less and less important the higher above sea level you are... so it may not be the end of the world.

Good point, but sadly most of my driving is at sea level. It's on road trips that I get to enjoy the mountain roads. But even in town, I haven't been disappointed, of course I don't know what I'm missing. I'm just hoping that 90 is close enough & the dealer stands behind its sale in this 90-best market.

[Killer]

Let's say you drove 15,000 miles in a year at 20 mpg (I wish) for 750 gallons. If you assume a generous 35 cent per gallon hike over regular (here it is 20 cents), that works out to be $262.50 per year. And with that, you will get less performance and mileage which will even reduce the actual cost delta even more. Seems like a waste to run regular. Where I am, the operating delta would only be $150 per year. So, premium all the way. Just say no to regular. Might as well enjoy the better gas which usually includes other performance enhancing qualities like cleaners, etc.


Great post!!! Thank you.

[koala]

Good point, but sadly most of my driving is at sea level. It's on road trips that I get to enjoy the mountain roads. But even in town, I haven't been disappointed, of course I don't know what I'm missing. I'm just hoping that 90 is close enough & the dealer stands behind its sale in this 90-best market.

Hell, I bet if you went around to a lot of gas stations advertising 91, they might not meet the grade.

There are certain cars that "need" (the ecu fuel maps can take advantage of, anyway) higher than 91 (WRX STi for example), which can be a big problem for any of us out west.. as 91 is typically the highest we see out here, where-as the east coast has 93 at a lot of stations.

[Mazda Lover]

Hell, I bet if you went around to a lot of gas stations advertising 91, they might not meet the grade.

If this was the case, the station would be in a lot of trouble as the rating is a MINIMUM rating. I like to think that I'm often getting higher octane than what I pay for, but probably not.

[HeavyH20]

Do you live/drive at high elevations? octane becomes less and less important the higher above sea level you are... so it may not be the end of the world.

Only for normally aspirated cars. You get a "free" octane point for about every 1000 feet above sea level. Turbo cars make their own atmosphere, so premium is required no matter the altitude.


Great post!!! Thank you.

No problem, even a blind squirrel finds a nut once in a while :)

[Mazdaspeedgirl]

Only for normally aspirated cars. You get a "free" octane point for about every 1000 feet above sea level. Turbo cars make their own atmosphere, so premium is required no matter the altitude. Good to know...

No problem, even a blind squirrel finds a nut once in a while :) he said nut... (sssh)

[koala]

Only for normally aspirated cars. You get a "free" octane point for about every 1000 feet above sea level. Turbo cars make their own atmosphere, so premium is required no matter the altitude.



No problem, even a blind squirrel finds a nut once in a while :)

Ah yes, I suppose turbo vehicles are exempt from this equation.

[koala]

If this was the case, the station would be in a lot of trouble as the rating is a MINIMUM rating. I like to think that I'm often getting higher octane than what I pay for, but probably not.

What if you're at a pump that has 87/89/91 all on the same nozzle? Maybe the person before you filled up with 87, and there's 5 litres worth of 87 still in the line? I'm just theorizing here.

I'm just saying that it's probably not exactly 91 octane, and it likely fluctuates.

But is it enough to worry about? No, I doubt it.

[Mazdaspeedgirl]

Chevron advertises that they are the only oil company that regulates and tests their gas for octane levels. It's all I use unless there is nothing else available.

Also, might I add that the one vehicle I have owned that I can definitely tell lower grades of gas by performance is my MX-5. If we use anything other than 93 on hot summer days we get pinging. Of course I expect to see a LOT of gunk on the valves when we breakdown the motor that is currently in him. Even detergent synthetic oils changed at 3K intervals and fuel system cleaners did not prevent this from starting at around 80K miles. Hence my use of regular Castrol. Now I have found much more benefit to synthetic gear lubes for the rear diff/tranny. But that is another story... :D
YAY NEO!!! (http://www.neosyntheticoil.com/) (first)

[koala]

Chevron advertises that they are the only oil company that regulates and tests their gas for octane levels. It's all I use unless there is nothing else available.

Also, might I add that the one vehicle I have owned that I can definitely tell lower grades of gas by performance is my MX-5. If we use anything other than 93 on hot summer days we get pinging. Of course I expect to see a LOT of gunk on the valves when we breakdown the motor that is currently in him. Even detergent synthetic oils changed at 3K intervals and fuel system cleaners did not prevent this from starting at around 80K miles. Hence my use of regular Castrol. Now I have found much more benefit to synthetic gear lubes for the rear diff/tranny. But that is another story... :D
YAY NEO!!! (http://www.neosyntheticoil.com/) (first)

You have to wonder if something else is at play if you're experiencing pinging below 93 octane along with needing very frequent oil changes. (theoretically you should be able to go 7,500 miles of hard driving (well, maybe change the filter half way) on a good synthetic.

Have you ever had any UOA tests done?

[HeavyH20]

Carbon build up within the cylinder chamber changes over time and changes the effective compression ratio as well as provide hot spots. Then, under pressure, the gas ignites itself without the need for spark much like diesel. Then you get the telltale knock. It also occurs if spark advance is too early, but pretty much all newer cars have knock detection and adjust spark retard accordingly. Higher octane gas has a higher boiling point and is more stable under pressure since there are more long chain molecules.

I just spoil my car with a half tank of 100 octane unleaded once in a while to keep things moving nice :)

Octane boost is not as effective on Turbo cars since it is simply an oxygenate and dilutes the gas. I usually avoid that except for emergencies when regular is the only choice.

[Mazdaspeedgirl]

You have to wonder if something else is at play if you're experiencing pinging below 93 octane along with needing very frequent oil changes. (theoretically you should be able to go 7,500 miles of hard driving (well, maybe change the filter half way) on a good synthetic.

Have you ever had any UOA tests done?

Oh well my timing is advanced a bit on the current motor (sssh). In case you didn't know, the timing on the 99-00 miatas is non VVT.
And it's not NEEDing frequent oil changes (lord knows there's no "change oil" light in the car like some GMs) but just knowledge of what goes on inside the motor when you drive it hard like I do. That and I am old school. dyno juice needs to be changed every 3k. :D

[Mazdaspeedgirl]

You have to wonder if something else is at play if you're experiencing pinging below 93 octane along with needing very frequent oil changes. (theoretically you should be able to go 7,500 miles of hard driving (well, maybe change the filter half way) on a good synthetic.

Have you ever had any UOA tests done?

Oh, and I didn't say it happened everyday; just on very hot days under heavy acceleration (95+ degree days floored up to 7K rpm).

[Mazdaspeedgirl]

Carbon build up within the cylinder chamber changes over time and changes the effective compression ratio as well as provide hot spots. Then, under pressure, the gas ignites itself without the need for spark much like diesel. Then you get the telltale knock. It also occurs if spark advance is too early, but pretty much all newer cars have knock detection and adjust spark retard accordingly. Higher octane gas has a higher boiling point and is more stable under pressure since there are more long chain molecules.

Nicely said. :) You prove my point about why my MX-5 tends to get a bit of knock under certain conditions. No VVT, advanced timing, and known carbon deposits all contribute to it.

It's amazing how some people can perceive octane boosters to make the fuel easier to ignite and "burn more fuel giving more power" when they actually do the opposite. Having almost a decade's experience in auto parts sales, I have heard a lot of people's theories. Not that it's so bad to be unknowledgable, it's just a means to pique one's educational inclination if they can get past the fact that a GIRL told them how it works. ;)