Is premium fuel really needed?
07-28-17, 09:06 AM
#61
Driver School Candidate
at the gas stations i go to, a tank of premium costs me around 2 dollars more than the same tank of regular would cost. 2 bucks isn't much at all. might as well stick with the 91.
07-28-17, 12:38 PM
#62
Lexus Champion
Around me premium is .70-.90 per gallon more than regular. A 15 gallon fill up runs about $10-$13 more than with regular so it's not insignificant. I use premium but one needs to consider this before buying a vehicle.
09-12-17, 11:06 AM
#63
I would not put anything lower than premium in a turbo-charged engine. I just don't understand why you would take the risk of long-term damage to save a few bucks throughout the year.
Let's assume 12,000 miles per year, 25MPG as average, equates to 480 gallons per year. If the difference is 50 cents per gallon, we're talking about $240 a year in savings.
Do you really want to risk damage to your $40K+ vehicle by saving $240 a year?
Not worth it to me, but we are all allowed to make our choices.....no one wants to accept the consequences though.
Let's assume 12,000 miles per year, 25MPG as average, equates to 480 gallons per year. If the difference is 50 cents per gallon, we're talking about $240 a year in savings.
Do you really want to risk damage to your $40K+ vehicle by saving $240 a year?
Not worth it to me, but we are all allowed to make our choices.....no one wants to accept the consequences though.
Jayinco really said it best. Why step over dollars to grab pennies?
I will say that in the manual it states you can use 87 octane if nothing else is available. If you were using 87, I would highly suggest to stay out of the pedal. Lower the boost, less chance of pre-detonation.
I'm running a water/meth injection system that starts flowing progressively at 5psi so I COULD probably get away with 87 all the time. I don't do that though.
A deeper question this brings up.. Is the octane rating established before or after the addition of the 10% ethanol? Ethanol has a octane rating of 113. So even as little as 10% would suggest a nice improvement of octane stabilization. (89.6 octane if I mathed right)
Last edited by skyshadow; 09-12-17 at 11:11 AM.
09-12-17, 06:30 PM
#64
I know when I was overseas all gas imported was the same...and home testing of gas from different octanes revealed all octanes were same...in this case the highest octane of 93 where I was at...japan. this was back in 99 and was done on a usa base gas station. are there any cheap octane testers you can buy and test your local gas? I heard most gas is shipped in bulk same octane and its enhanced with local detergents additives by region/locally????
http://newsroom.aaa.com/2016/07/aaa-...created-equal/
wife puts premium only, but I have been known to try different stuff
http://newsroom.aaa.com/2016/07/aaa-...created-equal/
wife puts premium only, but I have been known to try different stuff
Last edited by Torii; 09-12-17 at 06:38 PM.
09-13-17, 01:34 PM
#65
Pole Position
I know when I was overseas all gas imported was the same...and home testing of gas from different octanes revealed all octanes were same...in this case the highest octane of 93 where I was at...japan. this was back in 99 and was done on a usa base gas station. are there any cheap octane testers you can buy and test your local gas? I heard most gas is shipped in bulk same octane and its enhanced with local detergents additives by region/locally????
http://newsroom.aaa.com/2016/07/aaa-...created-equal/
wife puts premium only, but I have been known to try different stuff
http://newsroom.aaa.com/2016/07/aaa-...created-equal/
wife puts premium only, but I have been known to try different stuff
09-13-17, 01:58 PM
#66
yea, idk either now other than I have heard from oil people in alaska and in the gulf that refineries just make 1 octane and distributes it...once it gets shipped/sold who knows what happens...
09-14-17, 02:15 PM
#67
Pole Position
"I'm in the natural gas industry, but do have some insight into this. Ethanol is far less expensive to gasoline refiners/producers due to very heavy government subsidies. Pure ethanol, after it is fully refined, carries a much higher octane rating than pump gas. Refineries are sent less-expensive, lower-octane rated gasoline from suppliers which is then mixed with the 10% ethanol to achieve the overall rated octane of 87, 89, 93, etc. The higher that octane at the pump, the higher the octane the base gasoline must be prior to mixing. The base gasoline used for "premium" 93 octane fuel is typically right around 87 octane before it is mixed with ethanol to achieve the 93 octane. So, non-E 87 octane is basically the base gasoline for premium. This is why they are usually around the same price. Non-ethanol fuel is getting more expensive because fewer and fewer suppliers are actually making it. The "top tier" classification simply means the fuel meets a specific requirement for the purity of the base fuels and the detergent additive packages and that is all I use (Costco-Kirkland, BP, Shell, wish we had Chevron on the east coast). I don't have a non-E gas station anywhere near me or that would be my choice."
12-12-17, 06:15 PM
#69
Lexus Champion
you can use lower grade fuel, the computer will compensate and pull timing which may reduce overall MPG and performance, and should anything brake you might run into warranty coverage issues.
personally the savings of $1.50 -$3.00 a tank isn't worth head butting with a dealership over warranty issues, but to each their own..
A modern ignition system has some type of sensor to detect pinging or knocking, what ever you want to call it. The computer then calculates the base timing for all the cylinders. The computer then optimizes the timing for each cylinder individually. The computer keeps track of cylinders similar to how sequential fuel injection does. The computer then pushes the ignition advance on a cylinder until it detects a knock. When a knock is detected the timing is backed off slightly. This is the optimal timing spot for that cylinder at that specific time. After a couple of ignition events the timing is pushed again to find the next optimal spot. This process happens in each cylinder individually.
personally the savings of $1.50 -$3.00 a tank isn't worth head butting with a dealership over warranty issues, but to each their own..
A modern ignition system has some type of sensor to detect pinging or knocking, what ever you want to call it. The computer then calculates the base timing for all the cylinders. The computer then optimizes the timing for each cylinder individually. The computer keeps track of cylinders similar to how sequential fuel injection does. The computer then pushes the ignition advance on a cylinder until it detects a knock. When a knock is detected the timing is backed off slightly. This is the optimal timing spot for that cylinder at that specific time. After a couple of ignition events the timing is pushed again to find the next optimal spot. This process happens in each cylinder individually.
12-12-17, 07:31 PM
#70
Lexus Champion
Around me premium is .70 to .90 per gallon higher than regular so the difference is significant around $10-$12 more per tank. But still, with a small turbo engine like the NX premium or at least mid-grade is probably the way to go. There have been MANY threads on this.
12-12-17, 08:04 PM
#71
Intermediate
Just out today: AAA: Premium gas not worth the money for most vehicles.....
http://clark.com/travel/premium-gaso...ste-aaa-study/
and
http://miami.cbslocal.com/2017/12/12...t-worth-price/
http://clark.com/travel/premium-gaso...ste-aaa-study/
and
http://miami.cbslocal.com/2017/12/12...t-worth-price/
12-13-17, 04:05 AM
#72
Pole Position
This is probably the most heated debate on these forums. Do whatever makes you comfortable. I use 87 octane in our 2015 RX450h. Experimenting with the other two levels, I have noticed zero difference in gas mileage or performance. I have used 87 in cars that have required premium for over a million miles and have not had one problem.
A previous post of mine on the subject.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4
From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.
Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
All this being said to each his own.
A previous post of mine on the subject.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4
From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.
Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
All this being said to each his own.
12-13-17, 07:51 AM
#73
Lexus Champion
but the manual and the fuel door say premium unleaded fuel ONLY? its one thing if it says recommended. there is some leeway there then at least. but this one says ONLY. so that's what i would suggest you do.
12-13-17, 08:23 AM
#74
The RX450h is a normal induction V6 but the NX200t (NX300 for 2018 BTW) is a turbocharged I4.
Ford Motor is the only manufacturer I have seen actually advertise different HP with various fuels.
I can buy into the theory that mid-grade or even regular will work safely in the normal induction cars
but the forced induction applications should be considered very carefully. A heavy foot to merge in
traffic and the boost stays high long enough...shops can analyze to fuel in the tank...sorry you just
bought an engine?
Ford Motor is the only manufacturer I have seen actually advertise different HP with various fuels.
I can buy into the theory that mid-grade or even regular will work safely in the normal induction cars
but the forced induction applications should be considered very carefully. A heavy foot to merge in
traffic and the boost stays high long enough...shops can analyze to fuel in the tank...sorry you just
bought an engine?
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lexus114 (12-13-17)
12-13-17, 11:47 AM
#75
Pole Position
The cars that I have had that stated premium only which were most never had one problem running regular 87 octane. I never notice any difference in gas mileage or acceleration. My cars have been many Acura's and Lexus's. If a Porsche, I might feel different. I remember reading an article by an Acura engineer who stated as a customer it makes a consumer feel better about buying a car that says premium only.