I believe the owner's manual officially says that 87 octane is acceptable and 93 octane is recommended for optimum performance and fuel economy. Unlike with Ford's EcoBoost engines, however, Dodge doesn't actually tell you what the difference in performance or economy is on the 1.4T between 87 and 93.

 

He works at a Ford dealer and used the ecoboost as an example actually. I know there will obviously be a performance difference between regular and premium but he was also talking about actual engine problems down the road when you don't use at least mid-grade with a vehicle that has turbo.

Use premium. It's only $1.50 more a fill up over mid-grade and your injectors and turbo will love you for it.

There's quite a bit of a difference between regular and premium here in Ontario. Although gas is pretty cheap right now if/when it goes back up, paying over 30 cents more a litre than regular is quite a big deal.

 

Use premium. It's only $1.50 more a fill up over mid-grade and your injectors and turbo will love you for it.

 

We ran midgrade for several months in the Dart and thought it was doing as good as Premium. Ran one tank of regular and after going through about 1/2 of that tank, topped it off with Premium because I couldn't stand the difference in engine operation.

Went to only running Premium just before the wife took the Dart to the drag strip. We were averaging about 6.7- 6.8l/ 100 on the midgrade and noticed that it went down to 6.2-6.3l/ 100 with the Premium. We had already decided to only run Premium Before we noticed that change, but it Is an added Bonus that the Dart 1.4l turbo gets it's Best fuel economy on Premium.

BTW, while running that 1/2 tank of regular, the Dart climbed all the way into the 8.0+l/ 100 for the first and Only time! (worst we usually see, even in winter driving is 7.4l/ 100)

 

I use 91 grade from Costco.

 

To each their own, but my manual says 87 acceptable, 91 preferred. Unless you have your own aftermarket tune, our engines aren't tuned enough to have a difference between 91 and 93. Anyway, I always do 91. You could do 87 if you really wanted to cut costs.

 

The early versions of the 2013 manual say "91 preferred" for the 1.4T. The later versions (and the 2014/15 manuals) say "93 preferred". There were some revisions to the early 2013 manuals, so it's a good idea to go to the Dodge site and download the latest manual if you have an older one (I think there a 6 versions of the 2013 Dart owner's manual).

 

6! 6 bats!!!!!

 

Never used anything but 91-93 in the Dart, but from experience with "tunes" for the differing octane levels on my '98 RAM, I can say the extra $ to fill the tank is offset by the increased MPG.
Based on conservative driving, you will get additional distance from a tank of higher octane fuel (offsetting the price difference), but you have the extra get up and go available (if you choose to use it).
Also, the MPG variation between driving mellow, and having a little fun with the available power, is less than that seen using lower octane fuel, so if you're "having fun" it will cost a bit more, but not that much more... likely no more than the MPG loss from hard driving on lower octane.
I'm all for building and tuning around 91-93... that our Darts come this way is a plus in my book.

 

I ran 87 in mine once and struggled to get 28 mpg average. Running 89 get 33 mpg average even when having fun.

 

I'm getting nearly 37 mpg on 40 mi. trips with mostly highway driving at 65 to 70 mph. Around town so far I'm getting about 29. Since my Jeep was 18.5 on the highway and 12 around town I'm loving the new gas cost in my Dart!

 

I'm getting 32 all city, and 34 with mixed driving on shitty 85 octane here in Colorado. My dart seems to hate premium, gas mileage dives low, but power is better.

 

The only way this would be possible is if you drive more aggressively when you put Premium in, hence the "drop" in mpg. Otherwise there would be no way that a More Efficient running motor is going to get Worse mpg!

It would be like someone telling me I'm going to get Better mpg in my 2004 Hemi 4x4 if I run 87 octane vs 91 premium. Simply Not going to happen as the motor will run Detuned in order to run crappy fuel like that and get Worse mpg. (actually 2-3mpg worse, I tested that theory lol)

Now, I'm sure that some are Happy saving $'s running lower octane fuel and it's Nice to "fool" yourself into thinking there is no difference, but simple Facts tell a different story

 

I ran a few tanks of 93 and I thought it was ok. Last long road trip I took her (about 600 miles) I used 87 and the car ran perfectly and I got about 39.7 round trip average.

 

I ran four tanks of 89 and four tanks of 93 in my Dart when I bought it just a couple months ago. I got about .5 mpg more with 93 and didn't notice any change in normal every day driving so to me, 89 is perfectly acceptable.
That being said, since gas is still so cheap, I'm just running 93 since it's recommended. I may change that when gas prices go back up again, but who knows. It's 40 cents a gallon difference between 87 and 93 around here, so I'll definitely be paying attention!

 

I wouldn't put too much faith in driving habits in a 1.4T Dart since it is not easy initially to figure out how to get excellent mpg's from anything but strictly highway driving, at least in my experience. Unless you do some controlled freeway testing, making careful note of the instant mpg to see if you really are on flat ground, I don't see how you can prove anything to Chrysler. Anybody else live in CO who has a 1.4T that you can compare to?

 

@kayfabe is less than 10 miles from me, we've tried to connect a couple of times

 

That would be perfect. You could drive alongside each other and relay the indicated mpg.

 

When you switch between different octane fuels, you have to do it little by little. Think of it this way, when you quit smoking all at once it effects you more and your body has a hard time with it. Just like if you normally run 91 in your car and switch to 87 the cars computer doesn't know what to do and it effects performance and fuel economy. If you do it little by little, like 1/8 tank increments, it may take a long time but your computer will learn and adapt and you could run a lesser octane fuel. But like it was said earlier in the thread, it's not that big of a deal cost wise in most areas to put premium in, so if you can do it then do it and if not then don't. At the end of the day it's your car so no one can tell you what you should or shouldn't put in it.

 

I have run 87 since day one with my Dart, I average 32MPG mixed driving, with no real attempts on my part to try and conserve. Just changed my plugs at 30k, no problem there, in fact they looked like they could go another 10-20k without issue.

I ran 93 octane a couple time (figuring I'd need to run more than one tank for the results to make sense) just to see what all the fuss was about, all I noticed was a 3mpg drop in my economy (no change in driving habit), I attributed that to the fuel having Ethanol added to boost its Octane (here in MI they don't tell you if it does or doesn't have E, so I can't substantiate that assumption).

Darts don't like ethanol it's not tuned for it, if your Premium fuel is ethanol free then I can see a boost, but if it isn't, you are probably doing more harm than good, assuming your 87 is E free of course.

 

In Ontario, most premium (91) or ultra (93) is E0 (ie. 0% ethanol), but I haven't seen 87 that wasn't E10 in many years. So I'm not sure if it's that my car hates 87 octane, ethanol, or both, but it doesn't drive very well on 87, and whenever I've put in a tank of 87 I've had to fill up 2 days sooner than normal (I usually fill up every other Friday on 91). It would be nice if Dodge specified what the difference is between the "acceptable" 87 and "recommended" 93. Ford has separate hp/torque and I think economy ratings for their EcoBoost engines running 87 and 91, the last time I checked.

 

Bringing back a cold topic. Sunday I was in line waiting to wash my car and my wife found the owners manual. I looked through the manual looking for fluid capacities and found that it says 87oct acceptable 91 recommended. I read through this thread I didn't find any definitive answer to sway me into running the 91/93 grade fuel. I've been running 87 out of habit from my previous vehicle but I've been seeing my mpg average right around 25.5mpg.

I'm not sure what to think, I was expecting a bit more MPG then 25 honestly. I'm not driving this car all that hard either.

 

The Only time We've ever seen worse than 7.Xl/100 was running regular fuel and only for 2 days. By the end of the second day it was in the 8l/100 for the first and Only time, regardless of how it is driven.

We only run premium 91 octane now and even on the coldest days of Manitoba winters it averages 7.4-7.5l/100 and I Drive the car. (no hypermiling) but I'm also a Smart turbo driver.

In the summer on premium its always in the low 6.Xl/100 since switching from mid-grade to premium. + Graded fuels are just Better for turbochargers. They don't leave ash deposits on the hot side of the turbo and everything simply works Better.

Having said that, to each there own, but if you're not happy with the MPG you're getting, I would suspect running regular is def part of the problem.

 

I've always run at least 91 in mine. I've flirted with 40mpg a few times. Generally 34 mpg with a heavy foot.
Im currently running 93 with no ethanol and seeing how that runs with my tune.

 

I only run 93, its worth the extra .20 just in better gas mileage, yet alone the extra powah. Once the water/meth injection kit is up and running it'll be a mute point really, but I will still run 93 even then.

 

Living in nebraska is not lucky. And we have blended gas to, the only way you can get 93 is with 10% ethanol. Most of the corn for Ethanol comes from here.

 

I always use 91 V-power btw no ethonol in that