Premium vs. regular fuel question

[ruxCYtable]

I'm sure this has been beaten to death on here so pardon my elementary question.

I'm a believer that if your car only requires 87 octane that it's a waste to run premium fuel, however, my gas card offers an at-the-pump rebate that makes the premium the same price as regular. Will it do any HARM to use premium if not required for my vehicle?

 

[yonyon]

No.

 

[Coprolite]

Only if that gas card also gives a discount that makes the regular gas even cheaper.

Running regular gas in a vehicle that needs regular gas works well, any benefit of more detergent can be offset with some Techron with all the money saved.

 

[ruxCYtable]

Originally Posted By: Coprolite
Only if that gas card also gives a discount that makes the regular gas even cheaper.

Running regular gas in a vehicle that needs regular gas works well, any benefit of more detergent can be offset with some Techron with all the money saved.
Does premium gas actually have more detergent? I didn't think it did.

Funny you mention Techron, however, as I threw some in with today's fill.

 

[RamFan]

Originally Posted By: ruxCYtable
Originally Posted By: Coprolite
Only if that gas card also gives a discount that makes the regular gas even cheaper.

Running regular gas in a vehicle that needs regular gas works well, any benefit of more detergent can be offset with some Techron with all the money saved.
Does premium gas actually have more detergent? I didn't think it did.

Funny you mention Techron, however, as I threw some in with today's fill.


Typically the additives go up with octane rating.

 

[JHZR2]

Originally Posted By: RamFan
Originally Posted By: ruxCYtable
Originally Posted By: Coprolite
Only if that gas card also gives a discount that makes the regular gas even cheaper.

Running regular gas in a vehicle that needs regular gas works well, any benefit of more detergent can be offset with some Techron with all the money saved.
Does premium gas actually have more detergent? I didn't think it did.

Funny you mention Techron, however, as I threw some in with today's fill.


Typically the additives go up with octane rating.


Have some citable data to prove that beyond hearsay?

 

[randomhero439]

http://www.shell.us/products-services/on-the-road/fuels/v-power/overview.html

"Shell V-Power contains the highest concentration of the New Shell Nitrogen Enriched Cleaning System"

"With five times the cleaning agents required by federal standards, Shell V-Power helps to clean up performance-robbing engine gunk even faster than Shell Regular grade gasolines."

http://mybpstation.com/fuels/invigorate-faq/

"Each and every grade of BP gasoline contains Invigorate, so when you're at the pump, you'll have your choice of BP Regular with Invigorate, BP Silver with extra Invigorate and Amoco Ultimate with maximum Invigorate."

Cant really claim the same extra additives in premium fuel for ALL gasolines. But you can speculate

 

[Trajan]

Cheaper to use Techron/Regane every 3,000 miles.

 

[gathermewool]

Does the rebate work on regular gas, too? If so, then follow the guidance provided in your very own post (second paragraph, first sentence) and use only the octane required.

 

[chevy_man]

It really wont change anything, and can cause more carbon buildup. When the octane rating goes up, you need an increase in either timing or compression to take advantage of the "premium" fuel. Some newer vehicles do this quite well (flex-fuel equiped in particular) but a majority won't have a noticible difference. (Unless, of course, your computer is already pulling timing to deal with spark knock from running too low of an octane rating.)

I run 91 only when I need to get away from ethanol. Ive seen what kind of cleaning cheap gas does, and how much carbon can build up from premium. Doesnt pay for itself.

If your vehicle runs fine on 85/87 that will continue to work.

 

[mechtech2]

There are some brands with more cleaners in the premium.
If so, go use it and take advantage of the offer.
You will not get carbon build up - that's nonsense.

 

[Clevy]

Didn't someone post a thread awhile back where some watchdog group tested all the majors premium and regular fuel to see if they were truly putting the advertised levels of additives or something like that?
I remember reading that Mobil had the highest levels of detergent in the regular flavour and shell v-power took the premium grade title for detergent levels.
I'm sure a search of the forum will bring up the info your looking for.

 

[eljefino]

Best answer is to run it in your own car and see if you get more MPG. A fancy scan tool may show if you're pulling timing from optimal. Many cars use knock sensors as an everyday part of feedback engine control-- not the emergency protection like in 1980s era turbos.

Get scientific and do a cost/benefit analysis. The premium for premium has never been lower, only about 5-6% now.

Not to mention but check various ethanol contents. IIRC 87 has been E-zero, 89 is E10 in parts of the midwest. IDK about premium.

 

[RamFan]

Originally Posted By: JHZR2
Originally Posted By: RamFan
Originally Posted By: ruxCYtable
Originally Posted By: Coprolite
Only if that gas card also gives a discount that makes the regular gas even cheaper.

Running regular gas in a vehicle that needs regular gas works well, any benefit of more detergent can be offset with some Techron with all the money saved.
Does premium gas actually have more detergent? I didn't think it did.

Funny you mention Techron, however, as I threw some in with today's fill.


Typically the additives go up with octane rating.


Have some citable data to prove that beyond hearsay?



Source

Shell and I believe Chevron also openly state that their premium octane fuels have more than their regular.

With that being said, I don't believe you should use higher octane ratings than is stated in the manual. In the Charger I use 89 because the manual states 89 is recommended but 87 is acceptable. In the Sebring, 87 gets used because the manual states 87 is recommended.

Moral of the story, just use what is stated in the manual. Unless you've got modifications that require higher octane of course.

 

[badtlc]

My mazda3 calls for 87 but due to the higher compression I run 91 or 93 in it. I don't have much time spent on the 87 but i average more than the EPA HWY rating of 39 MPG for my commute to work which is not all highway and not all that long.

IMO, companies are pushing the lines to list an engine at 87 octane while getting compression high as possible that they allow more "normal" timing retardation than you'd expect. It seems many different modern cars now days will pull the timing in everyday driving on 87 octane on hard accelerations or under heavy loads going up hill at lower RPMs. I like not having to worry about it.

 

[cchase]

Even some of our more lowly cars do run closer to optimal timing with mid and high octane fuels. I've never noticed enough of a fuel economy advantage to make it cost effective, however.

Originally Posted By: JHZR2

Have some citable data to prove that beyond hearsay?


There was a report done by a news station in Michigan that has floated around the forums a few time where they measured additive levels at various gas stations in the different octane levels. Premium did reliably have the highest detergent levels, but I still think if that's all you were trying to buy with premium, it would be cheaper to just buy some Techron.

EDIT: Found it Fuel Additive Levels Test

 

[ARB1977]

Originally Posted By: cchase
Even some of our more lowly cars do run closer to optimal timing with mid and high octane fuels. I've never noticed enough of a fuel economy advantage to make it cost effective, however.

Originally Posted By: JHZR2

Have some citable data to prove that beyond hearsay?


There was a report done by a news station in Michigan that has floated around the forums a few time where they measured additive levels at various gas stations in the different octane levels. Premium did reliably have the highest detergent levels, but I still think if that's all you were trying to buy with premium, it would be cheaper to just buy some Techron.

EDIT: Found it Fuel Additive Levels Test

Interesting. I'm surprised they didn't test Chevron.

 

[Errtt]

My work beater (98 Rav), trying premium might run smoother while sitting at a stop in gear, but is a little more sluggish on acceleration. Get less mpg too.
Does better on the regular. More pep on acceleration. (wait a minute... pep on a Rav-4.... doesn't seem right to say that).
Guess it doesn't pull timing to like premium.

 

[hemitom]

In my 300 the manual states 87 to 89 octane with 89 recommended, i have run a few tanks of 87 and i was always suspect that 89 was no different. Well it was the car does have more pep and runs stronger on the 89, as for fuel mileage to many variables to get a true figure but i suspect its slightly better on the 89. In the kia no difference was felt between the 87 and 89.

 

[cchase]

Originally Posted By: ARB1977

Interesting. I'm surprised they didn't test Chevron.


My suspicion is there are no Chevron stations in MI. I know there are none in the Northeast.