[virgilangelo]

Greetings,
I recently got a 2016 Smart ForTwo and it came with a recommendation to use premium unleaded gasoline. This is the first car I have ever owned that made such a suggestion. Does it make a noticeable difference in performance or strain on the drive-train? Also, there are a number of gas treatments on the market. Do they really do anything or is it mostly snake oil?

 

[jwight]

Just my .02, but the premium vs. lower octane discussion has been done to death here. M-B recommends premium, let your conscience be your guide. As for additives, the owners manual recommends against them. It's your car...

 

[smark]

^^^^^Ditto, Use premium fuel. Stay away additives. Once every 6 months, at a fill up. Use some fuel injector cleaner.

 

[virgilangelo]

Just my .02, but the premium vs. lower octane discussion has been done to death here. M-B recommends premium, let your conscience be your guide. As for additives, the owners manual recommends against them. It's your car...

I apologize if I I inadvertently flogged a horse long dead. That's part of why I posted to the new users forum.

 

[Jo e Lefors]

Greetings,
I recently got a 2016 Smart ForTwo and it came with a recommendation to use premium unleaded gasoline. This is the first car I have ever owned that made such a suggestion. Does it make a noticeable difference in performance or strain on the drive-train? Also, there are a number of gas treatments on the market. Do they really do anything or is it mostly snake oil?

If you put Premium gas benefit into the
Search Community and enter, you will come up with an answers to your questions.
good luck

 

[jmartinsmart]

I ran premium in my 2008 until it was out of warranty... then I switched to regular unleaded. Didn't notice much of a performance hit, but it was an older car at that point.

In my 2016, I've only run premium, and I do think it's giving me better mileage than if I dropped back to regular.

Did running regular contribute to the ultimate demise of my 2008's engine... perhaps.
Am I going to take that chance with the 2016... naw.

Just my $.02.
Jim

 

[Jo e Lefors]

What is the upside for auto manufacturers recommending premium if they don't have to?
I'm sure it is not "Let's increase the cost of ownership and reccomend premium fuel, just for the fun of it.

 

[Mjolinor]

Most people will not use it so they have a get out if it blows up.

Not at all cynical me.

 

[smark]

I own 2 vehicle that require 91 octane fuel. The smart car, and 500 Abarth. Whats funny we also have a Honda Fit too. That uses regular fuel. It achieves better fuel economy, then the smart or the Fiat. It much bigger, Hold 4 people comfortable. Has a 130 hp engine.

 

[jetfuel]

…it’s a high compression engine…then you strap a turbo…more compression
…the car’s brain can only go so far on timing to prevent detonation from the sensor…you can’t hear it…radio too loud…car is too…premium gas is the only thing that can keep you from blowing a hole on top of the piston…or around the rings…
…if you’re running reg fuel and boosting next time you pull the plugs take a closer look at them…see little black dots all over them???…that’s detonation…

jetfuel…cheaper to buy premium than engines…

 

[1983JZR3W]

jetfuel…cheaper to buy premium than engines…

And much easier to put in the car......

 

[vadsoom]

I’ve made two cross-country trips in two different Smarts in 2021 and found there is a huge difference in fuel economy with premium fuel.

It was obvious which fuel was better quality. A though I never used anything under 91 octane, I could tell within the first 10 miles of each fuel stop if the gas was good or not. Good gas was consistently 43-45 mpg on my Ultraguage. Crappy gas was 34-36.

So obvious was the difference, I stopped and bought a dozen bottles of octane boost and used it whenever the fuel economy warranted. It works.

It would have been interesting to take a sample from each fuel station and have the gas analyzed to see which ones were filling their “premium” tanks with “regular” but still charging .50 more per gallon.

Consistency the best fuel I observed was from Mobil stations. The worst, from Loves.

YMMV… literally.

 

[smark]

I used 93 octane once, on our Mo Kan smart club venue to Jamestown Missouri. There wasn’t any other octane offered. I got the best fuel economy ever out of the car. But was it worth the extra cost for fuel. We only use Phillips 66 gasoline when available. 91 octane. Quick trip gas is excellent too. Mobil here in town, is the only Station that offers 93 octane.

Our club took a weekend event to Madison county Iowa. The little town only offered 87 octane. On the way back home. Didn’t notice any differences in performance. The only time I tried that.

 

[jetfuel]

…the bride‘s car only uses 87 and it is 45-49 mpg on 80k miles since new…it’s the way it is driven…
…me on the other hand is 93 oct for a constant 36-39 mpg…but…had to make a quick trip to north Indiana so I mixed a little blend of 97 oct for a full tank and boosting a lot I was surprised to achieve 42 mpg…I’ve done 100 LL but it turns the O2 sensors and exhaust tips milky white …
…octane makes a difference

jetfuel…next blend 99 no lead

 

[Richard LeBlond]

…it’s a high compression engine…then you strap a turbo…more compression
…the car’s brain can only go so far on timing to prevent detonation from the sensor…you can’t hear it…radio too loud…car is too…premium gas is the only thing that can keep you from blowing a hole on top of the piston…or around the rings…
…if you’re running reg fuel and boosting next time you pull the plugs take a closer look at them…see little black dots all over them???…that’s detonation…

jetfuel…cheaper to buy premium than engines…

On 2-12-1922 I drove rt from Phoenix to Yuma,Az at 65mph/cruse control on regular fuel. after driving 200+ miles, when I stoped the car,code P006e check engine lite on. I would reset it and then continue. To keep it out of detonation, I would be very careful to keep engine out of boost---(almost impossible) as every time the trans would upshipt, the engine would go into boost. SO, I went 390.9 miles, low fuel lite came on at 382 miles . refueled at390.9 miles, topped off at 7.468 gallon at overflow. So, 52.3 mpg. When I topped off , i used Premium fuel after resitting P006e code. Interesting observation: As I suspect, the ecu software is very sophisticated because the engine performance was greatly reduced and my conclusion is that detonation was detected and the software de-tuned the engine to prevent detonation engine damage, how I'm but not sure but power was definitely limited---no acceleration!! Several things contribute to detonation. Some are 1) temperature, ign timing, compression ratio/boost, fuel grade. Drove the car after refueling, found power was not there, definatly powerlimited!! Drove another 30 miles home. Then this morning , tried topping off fuel again. Noticed great improvement in power----had returned to what I call normal. Also, on regular fuel, The car would slow down on upgrades because with cruse control on, there wasn't enough power to maintain constant speed.
Botton line, run regular fuel on this car--2016 453 with 90k miles,software is smart enough to automatically adjust tuning to prevent engine damage from poor grade fuel!! And then return tune---after some time to previous settings once time/ mileage or some other parameter verifies the condition has been resolved. Strictly an observed possibility. Unfortunately I don't have copy of the software to see what the code is doing. Perhaps the factory shop/service manual has a description of software functions. Next time I am taking a long trip, I can use regular fuel with some confidence the engine will be de tuned automatically. I will also repeat this experiment with ethanol free regular gas as this fuel has a much higher energy content per pound. Look at Reid vapor pressure of gasoline, Important to know about this---makes a difference in fuel mileage as fuel additive packages are changed based on seasons/ locations etc.

 

[SMARTKAR]

Just my .02, but the premium vs. lower octane discussion has been done to death here. M-B recommends premium, let your conscience be your guide. As for additives, the owners manual recommends against them. It's your car...

Used what’s recommended

 

[Richard LeBlond]

On 2-12-1922 I drove rt from Phoenix to Yuma,Az at 65mph/cruse control on regular fuel. after driving 200+ miles, when I stoped the car,code P006e check engine lite on. I would reset it and then continue. To keep it out of detonation, I would be very careful to keep engine out of boost---(almost impossible) as every time the trans would upshipt, the engine would go into boost. SO, I went 390.9 miles, low fuel lite came on at 382 miles . refueled at390.9 miles, topped off at 7.468 gallon at overflow. So, 52.3 mpg. When I topped off , i used Premium fuel after resitting P006e code. Interesting observation: As I suspect, the ecu software is very sophisticated because the engine performance was greatly reduced and my conclusion is that detonation was detected and the software de-tuned the engine to prevent detonation engine damage, how I'm but not sure but power was definitely limited---no acceleration!! Several things contribute to detonation. Some are 1) temperature, ign timing, compression ratio/boost, fuel grade. Drove the car after refueling, found power was not there, definatly powerlimited!! Drove another 30 miles home. Then this morning , tried topping off fuel again. Noticed great improvement in power----had returned to what I call normal. Also, on regular fuel, The car would slow down on upgrades because with cruse control on, there wasn't enough power to maintain constant speed.
Botton line, run regular fuel on this car--2016 453 with 90k miles,software is smart enough to automatically adjust tuning to prevent engine damage from poor grade fuel!! And then return tune---after some time to previous settings once time/ mileage or some other parameter verifies the condition has been resolved. Strictly an observed possibility. Unfortunately I don't have copy of the software to see what the code is doing. Perhaps the factory shop/service manual has a description of software functions. Next time I am taking a long trip, I can use regular fuel with some confidence the engine will be de tuned automatically. I will also repeat this experiment with ethanol free regular gas as this fuel has a much higher energy content per pound. Look at Reid vapor pressure of gasoline, Important to know about this---makes a difference in fuel mileage as fuel additive packages are changed based on seasons/ locations etc.

3-14-22 update. After the above trip/regular fuel use, I verified the engine tune, after refueling, was detuned only allowing 2psi boost!! Software was smart enough to change tuning (drop Power to prevent damage. This is exactly what I would like to do so that for long trips, I could safely burn regular! Boost was limited to 2psi, power was reduced!! Then the problem, how do I get the origional 15 psi boost back to normal? Last night, I disconnected the battery, came out this morning and reconnected battery. WOW, 15 PSI boost is back!! This makes a dramatic difference in performance.
Burning question----How to turn on this reduced power setting to run regular fuel? It was automatically turned on by running regular fuel ----and I suspect detonation was detected, code P006e turned on & program reduced max. boost to 2psi.So clearing out theP006e code did not bring back the 15psi origional tune. The oem software is ---quite smart! I would like to see a technical description of the ecu program and what it is doing!
I suspect the program is designed because there is no way the grade of fuel is controlled worldwide. Perhaps with time or driving for a time without detonation, the program would turn bask to normal. Does anyone out there know about this?