Got 10% better mileage with premium!

[StevieC]

Originally Posted By: ravenchris
2007 Sonata, stick. Last week the service manager drove my car and agreed that it pings. He suggested using mid grade gas.
What engine do you have?

I had a ping in my Santa Fe, and I switched brands of fuel and it went away...

 

[ravenchris]

Yes.

 

[ravenchris]

2.4 l

 

[StevieC]

The 2.4 should run just fine on 87. I would check into the plugs being the wrong type (heat range). If not that, try switching brands for a few fill-ups. Also check the EGR valve for a lazy diaphragm or plugged hole or the O2 sensor for inaccurate function.

 

[Cup of Joe]

Originally Posted By: ravenchris
Yes.


Not everyone seems to recognize a ping problem. Cars these days are to insulated to hear the engine ping without the windows down and a barrier or obstruction to reflect the sound back at the driver.

 

[ravenchris]

Gas is from BJ's and Sams. Car was checked, no codes. Will try another brand. Thanks for your opinions.

 

[Cup of Joe]

Originally Posted By: StevieC
The 2.4 should run just fine on 87. I would check into the plugs being the wrong type (heat range). If not that, try switching brands for a few fill-ups. Also check the EGR valve for a lazy diaphragm or plugged hole or the O2 sensor for inaccurate function.

You can check any of that if you like. Its none of them from experience. Fuel brand is always a good idea if its intermittent.

I should add I am running a step colder plug then factory, no effect.

 

[StevieC]

I have had pinging caused by an 02 sensor on my Pontiac 6000, then it returned with a vengeance and turned out to be the EGR. I also had the problem on my partners Escort. Was the 02 sensor on it making it run extremely lean.

 

[Cup of Joe]

Originally Posted By: StevieC
I have had pinging caused by an 02 sensor on my Pontiac 6000, then it returned with a vengeance and turned out to be the EGR. I also had the problem on my partners Escort. Was the 02 sensor on it making it run extremely lean.



A pontiac 6000 is OBD I if that. You can pull the lead off of the O2 on a OBD I and it can take days before you set a DTC. Not the case these days. I'm not aware of any asian brands that even use EGR on 4 cylinders. The current bread are using CVVT system and cam fazing of the exhaust cam to get the same results. With dual 4 wire O2 sensors its much less likely to have a lean condition without setting a DTC, its also more costly to fix since 1 4 wire O2 is tripple the cost of a 2 wire OBD I O2 sensor.

 

[StevieC]

Nope... Within a minute the SES light would come one... Not days my friend... I have actually owned this car and think I would have first hand experience.

 

[Cup of Joe]

Originally Posted By: StevieC
Nope... Within a minute the SES light would come one... Not days my friend... I have actually owned this car and think I would have first hand experience.

Interesting. Other OBD 1 cars I have owned literally took days to register a O2 code.

 

[StevieC]

It would show me the SES light here/there for some unknown reason that I never did sort out, however with the O2 sensor it would always come on right away...

It was a crazy system.. You could disconnect so many things and the engine would continue to run without much mileage variance... Made me wonder why it had a computer and not a Carburetor.

 

[Cup of Joe]

Late 80's and early 90's camaro owners reported similar. Some could disconnect and remove the MAF sensor and the car would be faster on the 1/4 mile with no SES.

Not the 89 IROC I owned but some.

 

[smokey1]

I would think a an ethanol based premium gas would slow done the burning ( ignition ) of the fuel mixed with ethanol ( less mileage ) making for better fuel economy . Just a thought .

 

[Audi Junkie]

10% is a LOT, if you think about it.

 

[Eddie]

10% ethanol yields 4.3% lower heat value so you would expect a drop of only 4.35 in mileage. Difficult to believe a 10% increase using premium instead of 87 octane. If you vehicle is engineered to run on 87 and you are getting 10% better on premium, then something is wrong with you engine tune IMO.

 

[Rabbler]

E10 stoichiometric is also lower (numerically) around 14:1 vs 14.7:1 so wouldn't that be a double hit on the mpg?

Less energy and a richer mixture?

 

[Quest]

placebo effect.

Q.

 

[Gary Allan]

Originally Posted By: TaterandNoodles
Originally Posted By: StevieC
Nope... Within a minute the SES light would come one... Not days my friend... I have actually owned this car and think I would have first hand experience.

Interesting. Other OBD 1 cars I have owned literally took days to register a O2 code.


I think you mean illuminating the MIL. My 92 Caravan would have codes that never lit the MIL. You only saw them with the right scanner or doing the key (on-off-on-off-leave on) thing and counting the flashes.

 

[StevieC]

No it was a big orange light that said "Service Engine Soon". Was a car from the 80's.