I am smart enough to know that putting premium fuel in a vehicle that only requires regular is just a waste of money unless I am towing or hauling heavy loads. However I now have two vehicles with there own variances of cylinder shutdown modes that allows the engine to run on less cylinders. I cant help but wonder if during these times if running 93 Octane is better for the engines when there are less cylinders producing power to push these trucks and maybe help a little by less timing retard and therefore even squeezing out more .1% mpg Whats everyone elses thoughts?
Premium Fuel & Cylinder Deactivation
- Thread starter 05Blazer
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Give it a shot, it may help but for possible other reasons as well. (If so, who cares as long as it works?) Be as controlled as you can WRT outside air temp and other variables and run several tanks.
If you can get payback that matches the increased price, that's swell, you'll get more miles to a tank which will be convenient.
Came across an engineering article that says knock sensors are now routinely part of the feedback control system and not the crude 1980's emergency shutdown devices of that era.
If you can get payback that matches the increased price, that's swell, you'll get more miles to a tank which will be convenient.
Came across an engineering article that says knock sensors are now routinely part of the feedback control system and not the crude 1980's emergency shutdown devices of that era.
Originally Posted By: 05Blazer
I am smart enough to know that putting premium fuel in a vehicle that only requires regular is just a waste of money unless I am towing or hauling heavy loads. However I now have two vehicles with there own variances of cylinder shutdown modes that allows the engine to run on less cylinders. I cant help but wonder if during these times if running 93 Octane is better for the engines when there are less cylinders producing power to push these trucks and maybe help a little by less timing retard and therefore even squeezing out more .1% mpg Whats everyone elses thoughts?
Modern fuel injected engines can adapt to higher octane fuels.
Most car makers do not require 87 octane. If you look at the owners manual, I'd be willing to bet it states you use a "minimum octane rating of 87" "or higher".
The ECU's in today's cars can make slight adjustments and use higher octane.
Is the ever so slight increase in performance worth the cost? (could be little no increase in real world driving or it could be 3,4,5+% bump in MPG and/or HP)
Thats what ya gotta answer for yourself.
I am smart enough to know that putting premium fuel in a vehicle that only requires regular is just a waste of money unless I am towing or hauling heavy loads. However I now have two vehicles with there own variances of cylinder shutdown modes that allows the engine to run on less cylinders. I cant help but wonder if during these times if running 93 Octane is better for the engines when there are less cylinders producing power to push these trucks and maybe help a little by less timing retard and therefore even squeezing out more .1% mpg Whats everyone elses thoughts?
Modern fuel injected engines can adapt to higher octane fuels.
Most car makers do not require 87 octane. If you look at the owners manual, I'd be willing to bet it states you use a "minimum octane rating of 87" "or higher".
The ECU's in today's cars can make slight adjustments and use higher octane.
Is the ever so slight increase in performance worth the cost? (could be little no increase in real world driving or it could be 3,4,5+% bump in MPG and/or HP)
Thats what ya gotta answer for yourself.
If your refering to your Pilot, the compression is 10.5:1. Plenty enough to run premium fuel. It will take about 3 tanks of gas for the computer to adapt to the premium fuel.
i have a 2012 ram with the MDS feature. i run midgrade (recommended) or premium depending on the price gap from station to station. i usually tell no difference in fuel economy or performance at all. i haven't been brave enough to run regular in it yet. i know it wont hurt it, i just feel im neglecting my baby if i did... crazy i know
There is a Honda engineer on The Ridgeline forum that states the cheapest upgrade for the 3.5L is using premium fuel which equates to an extra 10HP and like 7lbs. I think I will continue to use premium in the 10.5:1 Pilot but will use top tier 87 Octane in the 9.9:1 Yukon.
Merry Christmas &
Happy New Year to all!
Merry Christmas &
Happy New Year to all!
05Blazer,
I have cylinder deactivation in my 08' Impala SS and I can say to some extend that if it saves fuel I haven't seen much. On my first big service this issue must be brought up and looked at.
In my manual it say premium fuel is recommened but not necessary as I'll notice a loss in performance only. For now as long as I can afford it I'll use premium. This week for super I only paid $34 bucks for half a tank of gas. Not bad in my wallet.
Durango
I have cylinder deactivation in my 08' Impala SS and I can say to some extend that if it saves fuel I haven't seen much. On my first big service this issue must be brought up and looked at.
In my manual it say premium fuel is recommened but not necessary as I'll notice a loss in performance only. For now as long as I can afford it I'll use premium. This week for super I only paid $34 bucks for half a tank of gas. Not bad in my wallet.
Durango
Originally Posted By: 05Blazer
Compression is a little higher in the SS series 5.3Ls I think it is 10:1 or a little more.
05Blazer,
Thanks for the info. In reality I don't know much about the GM 5.3 engines compression. So far it runs swell and so I'm a happy camper.
Durango
Compression is a little higher in the SS series 5.3Ls I think it is 10:1 or a little more.
05Blazer,
Thanks for the info. In reality I don't know much about the GM 5.3 engines compression. So far it runs swell and so I'm a happy camper.
Durango
Originally Posted By: donnyj08
i have a 2012 ram with the MDS feature. i run midgrade (recommended) or premium depending on the price gap from station to station. i usually tell no difference in fuel economy or performance at all. i haven't been brave enough to run regular in it yet. i know it wont hurt it, i just feel im neglecting my baby if i did... crazy i know
My 05 hemi gets better mileage on premium than the suggested mid grade. I think it's because here premium is not ethanol polluted except husky/mohawk stations,and the pure gasoline helps the mileage.
Mine is not an MDS engine however I have gotten 21mpg consistently on the highway when I'm not battling a prairie wind. Best I ever got with mid-grade was 17 but usually 14
i have a 2012 ram with the MDS feature. i run midgrade (recommended) or premium depending on the price gap from station to station. i usually tell no difference in fuel economy or performance at all. i haven't been brave enough to run regular in it yet. i know it wont hurt it, i just feel im neglecting my baby if i did... crazy i know
My 05 hemi gets better mileage on premium than the suggested mid grade. I think it's because here premium is not ethanol polluted except husky/mohawk stations,and the pure gasoline helps the mileage.
Mine is not an MDS engine however I have gotten 21mpg consistently on the highway when I'm not battling a prairie wind. Best I ever got with mid-grade was 17 but usually 14
Originally Posted By: rg200amp
Modern fuel injected engines can adapt to higher octane fuels.
This statement is way too general. How about "Some" modern engines.
Most can merely dial back the timing for bad fuel. Very few can ratchet things upward to adequately justify premium.
Modern fuel injected engines can adapt to higher octane fuels.
This statement is way too general. How about "Some" modern engines.
Most can merely dial back the timing for bad fuel. Very few can ratchet things upward to adequately justify premium.
05 -
You have some misconceptions.
Why is using premium for heavy loads smart? What benefit?
A stock vehicle with stock tuning should use it's recommended octane rating.
There is no more advance to be obtained in the computer. Only retard from getting a signal from the knock sensor..
You have some misconceptions.
Why is using premium for heavy loads smart? What benefit?
A stock vehicle with stock tuning should use it's recommended octane rating.
There is no more advance to be obtained in the computer. Only retard from getting a signal from the knock sensor..
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My car doesn't deactivate cylinders, but I'm trying an experiment with premium myself! I've been complaining how my 2004 Accord 2.4 gets crummy gas mileage with Costco regular since they put in so many additives and I'm sure alcohol in it. But I use it since the stuff is cheaper than most.
I used to get 30+ mpg regularly but it's down to 28- on the Costco Regular. So at 1/2 tank, I filled up with Costco premium. Presto, 29.2 mpg... Better thought I, so I filled up with premium again. We'll see... Seems to actually run a bit better on the premium too. I notice less on-off throttle snatch with the premium (it's a manual) plus it seems a bit more powerful as well. The price is about 30 cents more (10%) so if I can get 3 mpg better (10%), it's a break even and I get the psychological advantage of saying my car gets 30 mpg!!!
I used to get 30+ mpg regularly but it's down to 28- on the Costco Regular. So at 1/2 tank, I filled up with Costco premium. Presto, 29.2 mpg... Better thought I, so I filled up with premium again. We'll see... Seems to actually run a bit better on the premium too. I notice less on-off throttle snatch with the premium (it's a manual) plus it seems a bit more powerful as well. The price is about 30 cents more (10%) so if I can get 3 mpg better (10%), it's a break even and I get the psychological advantage of saying my car gets 30 mpg!!!
It does depend on what the "recommended" fuel actually is. Some manufactures may "allow" a lower octane fuel to be used even though it is not optimal, to give the perception of lower running costs. I notice most manufacturers use the term "minimum" not recommended.
The latest GM Holden V6 direct injection engine boasts it can run on any non diesel fuel at any pump in Australia. That ranges from 91-98 RON unleaded and E10 to E85. There has been a least 1 independent test done when all fuels were used and the results were as expected. The worst fuel economy was E85 and the best was 98 RON unleaded. For this test, given the prices we pay at the pump it did not make sense to use any Ethanol blend fuel even though it was cheaper. I think Premium unleaded (95RON) was the winner. I will add the test was not scientifically or statically valid.
The latest GM Holden V6 direct injection engine boasts it can run on any non diesel fuel at any pump in Australia. That ranges from 91-98 RON unleaded and E10 to E85. There has been a least 1 independent test done when all fuels were used and the results were as expected. The worst fuel economy was E85 and the best was 98 RON unleaded. For this test, given the prices we pay at the pump it did not make sense to use any Ethanol blend fuel even though it was cheaper. I think Premium unleaded (95RON) was the winner. I will add the test was not scientifically or statically valid.
FOUND IT!
The chemical tests conducted by Paragon Laboratories show widely different levels in gas samples collected on March 10.
BP 87 Octane ... 17.2 milligrams per 100 milliliters
BP 93 Octane ... 26.4 milligrams per 100 milliliters
Citgo 87 Octane ... 6.0 milligrams per 100 milliliters
Citgo 93 Octane ... 9.4 milligrams per 100 milliliters
Exxon 87 Octane ... 20.0 milligrams per 100 milliliters
Exxon 93 Octane ... 21.2 milligrams per 100 milliliters
Pilot 87 Octane ... 5.8 milligrams per 100 milliliters
Pilot 92 Octane ... 8.8 milligrams per 100 milliliters
Shell 87 Octane ... 16.2 milligrams per 100 milliliters
Shell 93 Octane... 31.0 milligrams per 100 milliliters
Samples were collected by WXYZ-ABC7, a Scripps-owned TV station in Detroit, according to standard testing protocol.
The chemical tests conducted by Paragon Laboratories show widely different levels in gas samples collected on March 10.
BP 87 Octane ... 17.2 milligrams per 100 milliliters
BP 93 Octane ... 26.4 milligrams per 100 milliliters
Citgo 87 Octane ... 6.0 milligrams per 100 milliliters
Citgo 93 Octane ... 9.4 milligrams per 100 milliliters
Exxon 87 Octane ... 20.0 milligrams per 100 milliliters
Exxon 93 Octane ... 21.2 milligrams per 100 milliliters
Pilot 87 Octane ... 5.8 milligrams per 100 milliliters
Pilot 92 Octane ... 8.8 milligrams per 100 milliliters
Shell 87 Octane ... 16.2 milligrams per 100 milliliters
Shell 93 Octane... 31.0 milligrams per 100 milliliters
Samples were collected by WXYZ-ABC7, a Scripps-owned TV station in Detroit, according to standard testing protocol.
I accidently posted in the wrong section.
Another good article on fuel additives.
http://www.patentinsightpro.com/techrepo...20Additives.pdf
Another good article on fuel additives.
http://www.patentinsightpro.com/techrepo...20Additives.pdf
supercity -
Yes, some mfrs accommodate low octane fuel, but this is not really the recommended rating.
The highest stated is always best.
I do not believe that cars rated for only regular will have any benefit with premium unless something is wrong.
Yes, some mfrs accommodate low octane fuel, but this is not really the recommended rating.
The highest stated is always best.
I do not believe that cars rated for only regular will have any benefit with premium unless something is wrong.
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