Does anyone know what happens to the car if you do use regular gas? Does a light come on, does it report something to Mini. Does it run awful? If so, what does it do.

I've been running mostly midgrade, 89 octane. I noticed that the car has been running pretty rough under light to moderate acceleration. Like its stuttering. Its a new car with only 8000 miles on it. I couldn't figure out the pattern. Seemed like warm humid days were the worst.

I'm now trying a tank of premium to see if that makes a difference, and at least to far, the stuttering seems to be gone. The engine generally feels perkier and gas mileage seems about 10% better. Is this to be expected?

Would regular gas make the stutter even worse with worse acceleration and mileage?

I've been wondering about running the tank low, then trying a gallon or two of regular to see what it will do. Then fill back up with premium.

 

Just run premium, that's what they run best on. You are not saving much now and you will potentially pay a lot more in future repairs. Resistance is futile.

 

You'll find many folks that have an opinion but nobody has facts. Facts such as tearing engines down after 200K miles that used premium and one that used regular.

MINI does recommend premium and that's what I use.

Something else: Comsumer's Report recommends using first tier gas on all cars. They did testing and showed the impact on engine parts. I don't remember the details but the report should be on-line.

 

Penny wise and pound foolish. You'll save a bit up front but replacing the knock sensor will eat that up and more, the voice of experience speaking.
Also, as Conrad mentioned, ONLY use Top Tier fuel. Here's the link.
http://www.toptiergas.com/
There are numerous threads on this very subject already discussed and archived and they all conclude the same. Don't try to cheap out.

 

A knock sensor is meant to detect preignition to be able to prevent damage to the engine. Its unlikely that it would be harmed by regular gas. Its the main structure of the engine that could be damaged by excessive knocking, however modern engines will alter timing and fuel injection to prevent knocking within a tolerance range.

One theory is that the stuttering is the engine altering timing etc. to prevent knocking and it causing the stuttering. I've never heard this engine knock.

I'm not necessarily trying to cheap out. I'm trying to figure out why the car has been stuttering and if there's something else wrong with the engine.

 

Run premium or mid "Top Tier" gas as recommended by the manufacturer. Only amounts to a few bucks difference per fill-up. My C7 gets the same premium 93 octane I run in the MINI.

Don't try and save a few dollars with less than the recommended gas. Replacing injectors is more expensive than the gasoline upgrade. Surprised this wasn't covered in when you went for the "Second Date" at the dealership.

If you find your self running out and the station only has mid or low grade non-top tier, it's okay to run on that in a pinch, but refill with the good stuff when you can.

If your car is knocking w/ the proper fuel..time to visit the dealership

 

A Knock sensor is a non-predictive sensor. In order for it to detect knock, a pre-detonation event has to already occur.
You will not hear the knock because modern knock sensor reacts instantly at the onset of pre-detonation. You'll need to log ign timing via OBD to really see.
Probably no damage if you're only keeping the car for a few years. Long term damage? Most definitely.

Just like you said, the ECU can only do so much within a tolerance range. I think you are beyond this range with your AKI89 plus high IAT from warm weather.

If you put premium gas and the problem goes away, then isn't it safe to say that it is indeed the low octane causing your problems? Just put proper high octane gasoline and call it a day.

 

It's all covered on page 166 of my owners manual, under the listing "Gasoline".

 

so all the gas comes down the same pipeline top tier is marketing

and what some people here call "premium" is "mid grade" for other states/regions so folks should really talk about octane rating

 

Use the grade recommended by the manufacturer.

In the case of octane, this really matters a lot, as pre-ignition or detonation is essentially the air-fuel mixture igniting too early (during the compression phase) and pushing back against the rising piston. It can and potentially will physically break expensive things in your engine, such as connecting rods/pistons/crankshafts.

It will also cause your dealer to void your warranty if you have detonation-related issues and they test the gas in your tank and determine it's too low in octane.

Octane is a measure of how resistant gasoline is to early ignition (it's not a substance). High octane fuel is harder to ignite but that's what you need in a high-compression turbocharged engine.

 

This guy is clearly a troll.

No one that owns a Mini is honestly this stupid, are they?

 

Experience would suggest otherwise.

 

He also made this exact same post a few months ago, and got pretty much all the same answers. Now he's doing it again. Troll.

https://www.northamericanmotoring.co...uel-grade.html

Anyway... you're going to burn up your valves and also your catalytic converter if you keep up this foolishness.

 

Seems obvious to me,

 

Well, I'd hope not but this topic comes up fairly often. The regular vs premium is only a debate on a vehicle can run on regular. Our cars are tuned/engineered to run on 89 or better. If you want a cleaner burn and you want your car to run as good as possible, get 93. If you don't give a ***** and think it's some kind of a conspiracy to get you to spend more money on gas run 87. At the end of the day if folks are so hellbent on not wanting to buy anything other than regular they need to buy a civic. Why buy a premium hatch back if you don't want to deal with premium hatchback requirements.

 

Yep, ran into the same thing in the Corvette forum even with the new C7 Z51 models. Some folk will spend a ton on the top end model and then post less than smart comments about what happens when they burn regular. Simply reading their owners manual or peeking inside the filler door it say's 93 Octane REQUIRED. It doesn't say recommended.

On my 2016 JCW Auto even in sport mode but driving long runs (50 miles or more) on the highway with cruise set to 70 I can get nearly 40mpg. I've never thought of buying even a gallon of regular nor will I. And here in GA premium is a .40 cent pop over regular ha ha.

 

ohh jez it's not the same guy stop being so offended

right in the owners manual for the F56 it says 89 octane minimum, this has nothing to do with a corvette that requires higher octane than most people can even buy, lolol you should probably recheck that 93 statement as 93 is not even sold in every state, guess those guys cant buy a corvette lolols

 

Mega, 1st JCW was making a metaphorical observation in an attempt to help folks suffering from rectal defilade in understanding the importance of using the right stuff for the machinery they are operating obviating the need for any future maintenance expenditures.

 

So here is my dilemma. I am the happy 8 day owner of a 2016 Cooper S with the JCW tuning kit ... exhaust + ecu tuning = 30 more horse power. Been reading this forum and owner manual says "Mini/91 octane, JCW/93 octane." So do I use 91 or 93 (due to extra 30 horsepower?)

Thanks in advance for the help ... and thanks to all who have helped my learning curve over the past eight days.

 

I would error on the 93 octane side. I have a 2015 MCS, same set up. I run top tier 93 octane at each full up.

Since I (you), spent the money for the JCW tune and exhaust (no including the considerable cost of the car itself), I'm looking to get the most performance I can from my investment. Low octane can't do anything but hurt the performance. Higher octane, can't do anything harm (more than likely help).

 

93 if available. I would be running 100 octane all the time if it weren't prohibitively expensive. Instead, I use the highest octane available at the pump. Preferably top tier.

 

somewhere around the gas cap will have the minimum octane rating for your MINI. mine shows 89. But I only go with Shell 91 because it 'feels' better. I've read people using lower 87 one getting misfires and check engine light due to high rpm, aggressive driving.

 

I just got the 2016 F56, recommendation was 91, minimum was 89. I use 89 because I can't find 91 at most gas stations, and 93 can be a lot more money here in NY. I use 91 when applicable tho. Definitely wouldn't use 87 though.

 

I use, for the little mileage that I do on my JCW F56 2DR HB...

The highest grade octane I can buy. I do that for turbo charged vehicles, that I own and that I like to enjoy with the intent they were built for.

In the USA, it is Sunoco Gold 94+ octane, and in Canada (they were taken over, but back in the day, ONLY Sunoco offered 94+ octane) I use Petro Canada Gold 94+ octane.

I did remove the battery on the vehicle, and let it relearn since switching exclusively to 94+ Octane.

The other inherit benefit, is that it is not the most popular choice (since it costs more, and few vehicles will actually benefit from higher octane) and hence there is less of a chance that you end up pumping gas into your vehicle just prior to a refilling truck that passed hours prior to you refilling your tank.

Cheers,

 

is the factory jcw tune aggressive enough to run up against the knock sensors with even 93 octane?

I don't know how aggressive factory tune is compared to 3rd party, on my 135i with a 93 flash I would never ever run less as it runs the timing right up to the knock sensors