Premium Fuel in Cars That it is Recommended

[CT8]

Originally Posted By: Gebo
Originally Posted By: Quattro Pete
Originally Posted By: Gebo
I wish I KNEW why Toyota RECOMMENDS premium.

Which Toyota recommends premium?


My Lexi
I had a 2006 Tacoma with the 2.7 engine [which I loved] that recommends premium gas for the best performance and yeah I read the manual. I gave the truck to my son.

 

[Alfred_B]

Surprisingly, My Audi calls for premium gas but gets better gas mileage with regular.

 

[OVERKILL]

30 cents a gallon difference? LOL! We are like 20 plus cents a litre difference up here

 

[skyactiv]

Sorry, I mixed up the 2018 Mazda 6 turbo with the Camry.

 

[Gebo]

Originally Posted By: OVERKILL
30 cents a gallon difference? LOL! We are like 20 plus cents a litre difference up here

Nope, that was a few years ago. Now it can be as much as 80 cents per gallon or 20 cents per liter.

 

[Linctex]

Originally Posted By: CT8
Only you can decide to spend the extra $$$ for higher octane gas. Higher octane gas allows more advance which equals more power and potentially more mpgs.


Yes, true - - but not $0.50 a gallon worth!!

 

[Linctex]

Originally Posted By: raytseng

Finally most gas stations only have premium and regular and midgrade is a mix. If you look closely there are visible gallon "odometers" for fuel dispensed, often you will see there are only 2 for premium and regular respectively, and both counters run when you pick midgrade because its mixing.


Yes, but it's actually a little cheaper mixing it yourself.

 

[OVERKILL]

Originally Posted By: Gebo
Originally Posted By: OVERKILL
30 cents a gallon difference? LOL! We are like 20 plus cents a litre difference up here

Nope, that was a few years ago. Now it can be as much as 80 cents per gallon or 20 cents per liter.


That's more in-line with our difference, with of course the acknowledged caveat that our gas is much more expensive.

 

[SHOZ]

Current prices per gallon in the town I usually get gas per GasBuddy; all withing a mile of each other.

Low- (for premium) 87-$2.39, 89-$2.69, 93-$2.89, Diesel-$2.69 Mom and Pop
High- (for premium) 87-$2.39, 89-$2.74, 93-$3.29 Diesel- $2.69 BP

Highest Diesel price is currently $3.05 a gallon.

 

[Kestas]

Originally Posted By: Audios
When I was at BMW tech school, they said to prove that premium cars run better on super, do 5 tanks back to back of regular and average the economy out, then the same with premium for 5 tanks. My instructor guaranteed that BMWs would return 4-5 better mpg overall using what the car called for. Its a false economy, youre paying less up front but more often for it. One tank could get you another 60-75 miles each tank, so by the 4th one, youre a whole tank behind with regular.

How long ago was that? There was a time when that was true. But modern prices have changed this avenue of thought.

We had discussion on this a year ago:
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4329050

Plus, there are three cars in my stable that are supposed to run on premium. I switched to regular and I haven't seen anywhere near a 4-5 mpg loss.

 

[28oz]

If my manual said "Recommended", I'd play around with different grades to see if there was any difference. However, my '90 300ZX states "Premium Fuel Required" on the dash, filler door, and the manual. So, premium is what she gets.

 

[raytseng]

89 is not 50 50 mix

 

[BrocLuno]

Originally Posted By: Win
Originally Posted By: HoosierJeeper
My LR3 recommends premium but I run regular, unless I'm in the mountains and working it hard.

That's a departure, then, from the older AJ-V8 in our '04 Jaguar - it "requires", not recommends, requires, premium, and it says so right on the inside of the fuel fill receptacle, so there is no way not to notice it.

I think the Solstice is a "recommends" 91 car - I found it under a cover and a pile of other stuff here at the lake house, and the fuel fill receptacle is unmarked, so, not required, I suppose.

Yeah, my wife's Jag "requires" premium too. But it's been fed regular for the last 100,000 miles and it runs just fine. She does not beat on it, so what's the point. It's a fancy grocery getter. No point ...

 

[slacktide_bitog]

If it's a turbo, use premium, even if it's just "recommended" and not "required"

If it's NA, regular will be just fine with no problems

 

[Wolf359]

Originally Posted By: Kestas
Plus, there are three cars in my stable that are supposed to run on premium. I switched to regular and I haven't seen anywhere near a 4-5 mpg loss.

Yeah it's funny how people think that regular gas will give you less mpg. The BTU content of regular and super is about the same although some actually say that premium has less. The mileage difference might be due to the different seasons, a/c running in the summer will lower mpg and winter gas has less btu than summer gas although with more oxygen due to the colder air, the car could make more power due to fixed air/fuel ratios.

You'd only really lose power if the car has to retard the timing and that might just be at WOT and probably most people don't drive like that.

The butt dyno is really an insidious piece of engineering.

I run premium all the time. I don't complain about it because if I wanted to run regular, I would have bought a car that just needed regular. Just part of the package that comes with owning a car.

 

[OVERKILL]

Originally Posted By: Wolf359
You'd only really lose power if the car has to retard the timing and that might just be at WOT and probably most people don't drive like that.

That's likely the same reason certain vehicles will lose gas mileage as well. If you've ever looked at the timing map for light load/cruise it is generally pretty aggressive. Having that retarded via knock-sensor can have an impact on mileage. Of course that's also tied to combustion chamber design, bore diameter and compression ratio.

Ms. Britches with her 4.09" bore and 10.9:1 compression ratio would likely lose more on lower octane than say a 32V Ford Modular.

 

[Wolf359]

Originally Posted By: OVERKILL
Originally Posted By: Wolf359
You'd only really lose power if the car has to retard the timing and that might just be at WOT and probably most people don't drive like that.

That's likely the same reason certain vehicles will lose gas mileage as well. If you've ever looked at the timing map for light load/cruise it is generally pretty aggressive. Having that retarded via knock-sensor can have an impact on mileage. Of course that's also tied to combustion chamber design, bore diameter and compression ratio.

Ms. Britches with her 4.09" bore and 10.9:1 compression ratio would likely lose more on lower octane than say a 32V Ford Modular.

While I'd say that's possible, a light load probably won't lead to high combustion chamber temperatures which can lead to premature detonation of fuel. Especially in cold weather with a colder air charge.

My car doesn't really say to just never use regular. It says that if they're out of premium, use regular and go easy on the throttle, no WOT til you can fill up with premium. But yeah, I suppose it could also be retarding the timing.

 

[Joenpb]

I'd try to find a better deal on premium. A station near me sells a lot of fuel and the difference between 87-91 octane is only 20 cents a gallon. My car idles smoother and drives better with premium.

 

[Kestas]

I actually looked through the video linked by BobsArmory. It shows the results of testing done by AAA to quantify the effects of running regular on mileage. It seems the loss in mileage is around 17% max, with real world loss at 2-5%. The loss is not great enough to justify running premium that costs 25% more. As long as your car doesn't ping, I think it's a no-brainer.

 

[OVERKILL]

Originally Posted By: Wolf359
Originally Posted By: OVERKILL
Originally Posted By: Wolf359
You'd only really lose power if the car has to retard the timing and that might just be at WOT and probably most people don't drive like that.

That's likely the same reason certain vehicles will lose gas mileage as well. If you've ever looked at the timing map for light load/cruise it is generally pretty aggressive. Having that retarded via knock-sensor can have an impact on mileage. Of course that's also tied to combustion chamber design, bore diameter and compression ratio.

Ms. Britches with her 4.09" bore and 10.9:1 compression ratio would likely lose more on lower octane than say a 32V Ford Modular.

While I'd say that's possible, a light load probably won't lead to high combustion chamber temperatures which can lead to premature detonation of fuel. Especially in cold weather with a colder air charge.

My car doesn't really say to just never use regular. It says that if they're out of premium, use regular and go easy on the throttle, no WOT til you can fill up with premium. But yeah, I suppose it could also be retarding the timing.


Generally the mixture is on the lean side under this scenario as well, which leads to higher temperatures. There are actually certain vehicles that are notorious for low/light load pinging under cruise, the 3V Ford is one of them.