Vehicles that require premium gas

[dodge man]

I've got a Dodge Challenger that I have a tuner for. The car is suppose to run mid grade 89 octane. With the tuner, I run premium. With the tuner I can log data to a lap top. This lets you look at all the data the cars computer sees real time or you can record it and play it back. There is two items the engine sees called long term knock and short term knock. The short term knock is no big deal, that means the engine sees knock briefly and pulls timing. For example my car with the tune installed will get a little short term knock at full throttle when it hits fourth gear.

The long term knock is a big deal. This means the computer is seeing a lot of knock on a regular basis. This gets stored in the computer and it starts pulling timing all the time. This would hurt performance and fuel mileage. The computer can be reset to delete the long term knock data but who knows how to do that?

Does you VW work the same way as my Dodge? Probably but maybe not. I'll just say running 86 octane might be a bad idea but 89 might be fine. More info might be found on some VW forums.

 

[Quebecguy]

We also do not have ethanol here.
Thoughts?

I don't know if you should use premium or regular but I'm pretty sure that almost all gas stations in Ontario are selling gasoline mixed with ethanol.

 

[The Fred]

What you NEED to do is use a quality injector cleaner every 10K miles or so. I replace a bunch of injectors in that engine and when they fail the engine will misfire when it just starts for a few seconds or so.

Techron, Liqui-moly LM2007 or BG44K all work quite well.

VW has had so much trouble with fuel injectors that there is extended warranty on them.

http://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM463188/CSC-10056164-3276.pdf

Regards, Fred

 

[Garandman]

Some cars say "premium recommended" Others say "Use premium gas" or the like which is more like "required". //

We had a Nissan Quest van that had two power ratings, one for Regular and one for 93 Octane. Difference was 4-5hp.

My 6 cyl Outback had Premium as "Recommended." I called SOA and asked what that meant and they said, "There will be no damage to the engine running regular." But the max power rating of 253hp was with Premium.

Have a turbocharged WRX and virtually always use Premium but that is a high-output engine. We've only used Regular in our 3.5L Ecoboost Transit.

 

[LD1]

We had a Nissan Quest van that had two power ratings, one for Regular and one for 93 Octane. Difference was 4-5hp.

My 6 cyl Outback had Premium as "Recommended." I called SOA and asked what that meant and they said, "There will be no damage to the engine running regular." But the max power rating of 253hp was with Premium.

Have a turbocharged WRX and virtually always use Premium but that is a high-output engine. We've only used Regular in our 3.5L Ecoboost Transit.

Perfect example of computers and engine management technology.

Computer will pull timing (reduce power) to run perfectly fine on 87 octane gas. But it is ultimately tuned for higher octane, and you will see best power and economy running what the engine is ideally tuned for (premium) in this case.

If an engine is ideally tuned for 87 octane and dont have to pull timing running it.....there is absolutely no benefit to running anything of a higher octane rating.

 

[clemsonfor]

My Toyotas say that best results and tests are done on premium but you can use regular no problem.

I have an 01 Highlander and an 04 Sequoia

 

[dfkrug]

BMW told me the premium in Germany were I bought the car is superior to California premium and I
found it to be true.

I don't know when it happened in Europe, Curt, but all the OBD2-compliant cars in the US and Canada
are supposed to have programmable ignition timing so the engine computer can ****** the timing
if it hears pre-ignition. OBD2 was on all US cars and gasoline-powered PU trucks by 1996.

These vehicles actually have one or more microphones on the engine block to pick up pinging.

My BIL now has a beemer 1150 motorcycle (not a "bimmer", or BMW car), and it has FI and
all that, but I don't think it is OBD2-compliant. So it many not have knock sensors. We don't
have smog tests for m/cs in California. He uses only 91-octane for his BMW.

That said, high octane gas is harder to ignite (a good thing for max spark advance and power),
and current octane boosters are alcohol-based. Europe gave up lead in gas later than the US,
so boosters with lead in them may have been sold for a longer time. None, now, of course.

Since 91-octane gas is harder to ignite vs. 87 regular, it may actually be beneficial to use
in chainsaws that don't have compression-release valves and tend to kick back on starting. I
am working with a friend to see if that can make his old 100cc saw easier to start.

 

[dickfoster]

Curious about your opinions. I'm a diesel guy, but recently bought a VW Tiguan SUV. It has the 2.0 liter turbo engine. It says it requires premium gas.

I rarely drive it as I am always using the trucks, and when I do, I'm not throttling on it. Nor does it get really hot here in the summers compared to the south.

So I'm wondering......is it really necessary? We also do not have ethanol here.

I have been putting premium in it, but a couple times filled it with regular when it was WAY cheaper. I noticed no difference in fuel mileage or power. Actually it seemed harder on gas with premium.

Thoughts?

For almost any forced induction engine whether turbo or supercharged you need premium fuel to prevent knock and pre detonation. Both of my vehicles require it as one is supercharged and the other sports a turbo charger. Buy the premium fuel or risk destroying your engine with predetonation. Regular fuel actually burns quicker than premium, so much quicker in fact that it burns down your engine. Count yourself lucky if you don't have your fuel polluted with ethanol as that stuff is pure crap and does nothing good. Ethanol is just another great American boondoggle foisted upon us by our idiotic politicians.

 

[ultrarunner]

I don't know when it happened in Europe, Curt, but all the OBD2-compliant cars in the US and Canada
are supposed to have programmable ignition timing so the engine computer can ****** the timing
if it hears pre-ignition. OBD2 was on all US cars and gasoline-powered PU trucks by 1996.

These vehicles actually have one or more microphones on the engine block to pick up pinging.

My BIL now has a beemer 1150 motorcycle (not a "bimmer", or BMW car), and it has FI and
all that, but I don't think it is OBD2-compliant. So it many not have knock sensors. We don't
have smog tests for m/cs in California. He uses only 91-octane for his BMW.

That said, high octane gas is harder to ignite (a good thing for max spark advance and power),
and current octane boosters are alcohol-based. Europe gave up lead in gas later than the US,
so boosters with lead in them may have been sold for a longer time. None, now, of course.

Since 91-octane gas is harder to ignite vs. 87 regular, it may actually be beneficial to use
in chainsaws that don't have compression-release valves and tend to kick back on starting. I
am working with a friend to see if that can make his old 100cc saw easier to start.

My right hand has never been the same from a chain saw kick back and that was in 2009...

When I bought my 325iT in Munich back in 2002 I asked BMW why the HP is slightly higher in Germany as opposed to the North American export model...

BMW said the premium fuel in Germany is higher octane so they can get more out of the motor.

On a side note I do notice marked improvement in mpg when I was traveling outside California with non California blend... 2006

The Rover I picked up earlier this year is also Premium...

 

[greif]

Here regular was $1.99 and premium $2.86 today,. Big difference