Why can't I run 87 in my car??

[Kennyredline]

Does anyone know what the fuck they're talking about?? All I want is better fuel mileage....I've changed my spark plugs, fuel filter, air filter had the vacuum system checked, changed my tire pressure....and then FINALLY....someone suggests lower octane fuel, and it works!!! A huge improvement in mileage!!!
BUT THEN I'm told I shouldn't be running regular gas in my car, that it's going to clog up my CAT-verter. They suggest removing it. I call around to arrange that, THEN I'm told that my O2 sensor will start throwing codes if I take out the Cat-verter.
Why can't I run 87 in my car?? The tag inside the fuel door says I can....why are Volkswagen service people telling me I can't run 87 octane in my car when the Volkswagen people who BUILT THE FUCKING CAR say I can?!?!?

[JRSC00LUDE]

Ummmm....go by the factory sticker/recommendation as opposed to the opinion of some asshat at the service desk.

.02


EDIT - Yes, removing cat will throw codes. It's unnecessary in your situation, I wouldn't consider it.

[G-ZUS]

-_-

[Kloubek]

Personally, I would never run a turbo car with a low grade gasoline.

With that said though, if it is working better for you then I don't *think* you're doing any harm. If the car notices a problem then it should retard your timing. This would (as far as I know) potentially result in lower power but no damage.

Anyone want to confirm that?

[JZS_147]

i'm going to go ahead and guess that this is an owning lol

[chkolny541]

go lower

[94boosted]

Originally posted by Kloubek
Personally, I would never run a turbo car with a low grade gasoline.

With that said though, if it is working better for you then I don't *think* you're doing any harm. If the car notices a problem then it should retard your timing. This would (as far as I know) potentially result in lower power but no damage.

Anyone want to confirm that?

:werd: Confirmed.

It should just pull timing (KR) and if you still missfire that should throw a CEL. I still wouldn't do it in my own car. Cutting back on power and potentially exposing your engine to more stress than nescessary all to save a few $'s.

[JRSC00LUDE]

Originally posted by 94boosted


:werd: Confirmed.

It should just pull timing (KR) and if you still missfire that should throw a CEL. I still wouldn't do it in my own car. Cutting back on power and potentially exposing your engine to more stress than nescessary all to save a few $'s.

If factory octane rating for a turbo engine is 89, presumably it's tuned to run perfectly fine/safe on 89. No? :dunno:

[OriginalGoods]

the only way it would affect the o2 sensor and throw any codes is if its after the cat, and i doubt it is.

[CapnCrunch]

The owners manual should tell you what grade to run. If you're manual says 87, and you run 91, you'll lose power and get worse mileage. Same goes the other way.

[J-hop]

as mentioned kenny you really need to hit up CVD's (or eurodrivers, or dasdubbers) forums and get someone to VAG com your car, something isn't right with your car. A simple OBD scan won't tell you shit unless your car is throwing a code a VAG com scan and data log is really the only way to go with these cars.

with the vag you can actually test the quality of your cat with a simple diagnostic process it runs which compares outputs from pre and post cat O2 sensors while revving the car to a certain rpm, it will also tell you if one of the O2 sensors is faulty (ie: laggy response, erroneous readings etc).

VAG cars are very touchy, so it could be any number of issues. I wouldn't run anything less than 91 on a 1.8T but that is just me. And as I said I am getting similar mileage to you in my 24v VR6 which I always run premium on, so something is definitely wrong.

[Twin_Cam_Turbo]

Doesn't the 1.8T have a recommended 91 octane and minimum 87 octane rating?

[D'z Nutz]

Originally posted by Kennyredline


http://forums.beyond.ca/st/268206/how-to-properly-title-your-thread-/

[Tik-Tok]

Originally posted by Kennyredline

Why can't I run 87 in my car?? The tag inside the fuel door says I can....why are Volkswagen service people telling me I can't run 87 octane in my car when the Volkswagen people who BUILT THE FUCKING CAR say I can?!?!?

What does the owners manual say? My Audi 2.7 twin turbo manual says run 91 octane, but also says I CAN run 87 octane, it just isn't recommended. If you run 87 for awhile (ie years), expect the cost savings to be nullified by maintenance.

What brand of gas do you use? Certain ones are shit for mileage (ie Husky,Mohawk, Tsuu T'ina Gas Stop), some are better (Shell).

Also look into chipping it (tuning). My APR tune gives me both more performance AND better fuel economy (at the cost of emissions, long live no Alberta exhaust regulations!)

[Sugarphreak]

...

[msommers]

Personally on any forced induction engine, I'd be running 91+. On high compression NA motors, they recommend 91 but plenty of guys on the G35 forums say they only use regular. Personally I wouldn't but apparently the ECU will retard the timing if it senses any knocking.

What's quite interesting though is the new F150 Ecoboost engine. A 3.5L V6 turbo'd engine that is recommended from the factory to run on 87! It's no slouch either, I imagine the tuning capabilities of that engine are going to be staggering.

[94boosted]

Originally posted by JRSC00LUDE


If factory octane rating for a turbo engine is 89, presumably it's tuned to run perfectly fine/safe on 89. No? :dunno:

Yup your right. I've just never seen a Forced Induction car that didn't recommend or need 91+.

[HiTempguy1]

Originally posted by msommers
It's no slouch either, I imagine the tuning capabilities of that engine are going to be staggering.

Direct injection y0, its a wonderful thing. Makes detonation extremely hard to happen as there is literally no fuel to detonate earlier then you want it to.

[03ozwhip]

Its a mechanicss thing I think... If you have 91 and detonate it, you expect the same volume of detonated gas regardless of the original source of the gas. It also tends to burn cleaner. So when you detonate 87, there is less volume of gas produced. The other part of it is that trhe car is sold to a world wide market.

gas mined in canada may be different from stuff sold in poland. So you have to really try to set a standard. 91 guarantees a min level of filtration, and a universal adoption. 87 can be some fucked up mixture pulled from tanzania and you would have no clue. Could be alcohol derived. 91 just sorta establishes a solid base line. More or less lol

[JRSC00LUDE]

Originally posted by 94boosted


Yup your right. I've just never seen a Forced Induction car that didn't recommend or need 91+.

Good point (well, minus this Ford apparently...), never really thought about it beyond what he said in first post about car label saying it's ok.

[Kennyredline]

I lost my owner manual last year at a dealership...funny how I left it in the parking lot, but someone keeps it...?:dunno:
Anyway, the tag inside my fuel door says 87-95, so unless
I"m reading it wrong, I should be able to run 87 and be ok. I called around, and got mixed answers, some say I'll kill my engine, others say even the newer turbo's can run regular gas.
Here's my fuel door...am I reading it right?
http://i1128.photobucket.com/albums/m481/Kennyredline/fueldoorjpgedit.jpg

[adidas]

Originally posted by OriginalGoods
the only way it would affect the o2 sensor and throw any codes is if its after the cat, and i doubt it is.

2 O2 sensors are found on the 1.8T, pre and post cat.

[RickDaTuner]

What you are seeing there are two different types of octane rating measurements.

the one that matters to north america is RON method which tells you to use 91

[theken]

I had a 1.8t. I ran 87 for 2 years. Never had a problem. Forced induction with 180 hp doubt u need premium

[Kennyredline]

^^ This is where I am...I used to run 87 before and it was fine. Now I'm getting kick-ass mileage, I have no idea why everyone is harping about higher octane....the mileage sucks!!(For me anyway..)

[g-m]

Originally posted by 03ozwhip
Its a mechanicss thing I think... If you have 91 and detonate it, you expect the same volume of detonated gas regardless of the original source of the gas. It also tends to burn cleaner. So when you detonate 87, there is less volume of gas produced. The other part of it is that trhe car is sold to a world wide market.

gas mined in canada may be different from stuff sold in poland. So you have to really try to set a standard. 91 guarantees a min level of filtration, and a universal adoption. 87 can be some fucked up mixture pulled from tanzania and you would have no clue. Could be alcohol derived. 91 just sorta establishes a solid base line. More or less lol jesus christ you have absolutely no idea do you?

[RickDaTuner]

Originally posted by Kennyredline
^^ This is where I am...I used to run 87 before and it was fine. Now I'm getting kick-ass mileage, I have no idea why everyone is harping about higher octane....the mileage sucks!!(For me anyway..)

the mileage with higher octane sucks for everyone.

Lower octane fuel has more BTU per mas, and because of this it is very unstable, relative to higher octane fuel.

High octane fuel has a slower burn rate, is more stable, but suffers from lower BTU amount during a burn.

This is why you get more mileage from lower octane fuel, you literary get more bang for the buck.


Using lower octane fuels in a forced induction car, may seem ok if all your are doing is driving it like a baby.
The car for most part will be off boost during light load inner city cruise, and will not suffer an major consequences.

A FI car under load and lower octane will suffer from heat soak and the build up of super heated carbon atoms in the combustion chambers.
It's these glowing particles, combined with the instability of low octane fuels that leads to detonation, or pre-ignition.

Those two conditions over time cause pitting in the main crank bearings, and abnormal wear on any engine bearing surface.

The PCM in cars can assume the octane rating of fuel from its knock count, derived from the knock sensor.
A knock instance is literally your engine smacking parts in a manner that it shouldn't causing a hammer to metal sound, which the knock sensor picks up.

That being said, force induction cars as of late are designed to run on 91+ fuel, and will always default their fuel tables there, since it does not know what kind of fuel is in the tank.
So if you run 87 oct or lower AKI fuels you will always be getting a knock in the engine on start up, this is becuase the PCM will always be checking to see if higher octane fuel could be found after a start up.

All in all, the damage that you will see from running lower octane fuel will not be seen right away.
It's something that reduces the life of an engine, and causes greater problems down the road.

Lastly low octane fuel will clog up cats because the instability of the fuel by nature will cause a rapid but incomplete burning of fuel, which results in higher than normal amounts of carbon clogging up the catalytic converter substrate.


:thumbsup:

[kvg]

On my old car if I didn't run premium I would loose power and mileage. I would just run what works. How many miles are on it? How's your turbo?

[Kennyredline]

Originally posted by RickDaTuner

the one that matters to north america is RON method which tells you to use 91

That's not what I'm reading....check the chart they provide. RON is for UK, Europe, South Africa & Australia;
(R + M )/2 Average of RON & MON. Usually 4-5 units lower than the RON. USA, Canada.
This chart suggests I can use 87 in my car....no?

http://www.torquecars.com/articles/fuel-octane-ratings.php

[03ozwhip]

Originally posted by g-m
jesus christ you have absolutely no idea do you?

wtf bitch?? chill out, it was an example of why its better for his car to run 91 octane, nothing more nothing less. take it with a grain of salt for all i care, im sure everyone else did.

[RickDaTuner]

Originally posted by Kennyredline


That's not what I'm reading....check the chart they provide. RON is for UK, Europe, South Africa & Australia;
(R + M )/2 Average of RON & MON. Usually 4-5 units lower than the RON. USA, Canada.
This chart suggests I can use 87 in my car....no?

http://www.torquecars.com/articles/fuel-octane-ratings.php

R+M is the methode for the US/Can you are right...

Ok you've got me confused that fuel door makes sense at the bottom. The top octane measuring method though, I have never seen that octane lettering? nor can I find out what it stands for...

:dunno:

[Kennyredline]

Originally posted by RickDaTuner


R+M is the methode for the US/Can you are right...

Ok you've got me confused that fuel door makes no sense at the bottom, but the top octane measuring method, I have never seen that octane lettering, nor can I find out what it stands for...

:dunno:
Well, I found that article to be pretty informative, and I checked out some other sites that verified what they said. I feel better about putting regular in my car, I mean, I did read the manual, and nowhere did it say I HAD to put a specific fuel in. I'll see how this tank plays out, then maybe try mid-grade and see if I get the same mileage with a little more cleaning for the engine.

[racerocco]

you can often get away with lower octane fuel here in calgary because of our altitude, but it possibly wouldn't work in Vancouver at sea level, my old car would run fine here on 94, but would detonate with 100 in Van, (13:1 comp)

[g-m]

Originally posted by 03ozwhip


wtf bitch?? chill out, it was an example of why its better for his car to run 91 octane, nothing more nothing less. take it with a grain of salt for all i care, im sure everyone else did. your post didn't make sense, violated the law of conservation of mass, and was just plain uninformed. If you don't know anything about fuel science and standards or just science in general its good practice to not post.

[CapnCrunch]

Originally posted by racerocco
you can often get away with lower octane fuel here in calgary because of our altitude, but it possibly wouldn't work in Vancouver at sea level, my old car would run fine here on 94, but would detonate with 100 in Van, (13:1 comp)

+1.

To the op, if you are 100% sure you are getting better mileage with the 87, then use it.

[Sugarphreak]

...

[HiTempguy1]

Originally posted by Sugarphreak


I thought that was only true for N/A cars and not ones with FI systems?

FI systems still become less efficient due to less dense air, but obviously since they compress the air, it is less noticeable. Wouldn't be the first time someone has come out here for the Rocky Mountain Rally and tried to hit their target boost settings they had out east. Can you say blown turbo from being overspun? :rofl:

[luxor]

Originally posted by g-m
jesus christ you have absolutely no idea do you?



Originally posted by g-m
your post didn't make sense, violated the law of conservation of mass, and was just plain uninformed. If you don't know anything about fuel science and standards or just science in general its good practice to not post.

:werd:

I thought it was a joke at first but then I realized he wasn't kidding.



Originally posted by 03ozwhip


wtf bitch?? chill out, it was an example of why its better for his car to run 91 octane, nothing more nothing less. take it with a grain of salt for all i care, im sure everyone else did.

Don't worry, I sure did.

[sillysod]

The 1.8T is designed to run on 91 NOT 87. I can tell you that without looking at your manual.

If you really feel that you are saving all kinds of money then go for it, but really how much can you save. I would understand if you had the F350 Triton V10 gas engine in your car, or even the VW 2.8L V6, but the 1.8T is great on gas as is.

[crapstixs]

In north america as per law, all vehicals sold must be able to run off 87 ron+mon with out any damage to the catalyst or the engine. is it the best, no. If the maunfacturer says its best to run 91, do so because thats what the pcm is tuned for. but you will not do any damage if you run 87.

[btimbit]

The octane content will not affect stoichiometric ratios in the engine...the ECU will adjust that measurement (air/fuel ratio). But it's best to always run the suggested octane rating in a car. Knocking/pinging can damage an engine.

Since you are running boost, then higher octane is better especially if the ambient temps are high. Especially if you're car is 'chipped'



I'd be looking at why the car gets such poor gas mileage to begin with, that seems to be the bigger issue. Scan it with VAG-Com, check the MAF, CTS, O2 Sensor, and AIT Sensor. Those are the most common problems for this sort of thing on a 1.8T.

Your car could also be running in limp mode, so again, the first thing I'd do is scan it with VAG-Com.


If you're worried about the cat, you could just remove it. There are a few ways of preventing a CEL from popping up because of it. You could try a spacer for the post cat 02 sensor; http://store.42draftdesigns.com/O2-Sensor-Spacer_p_306.html

Or you could get some software to delete it entirely.

[Cos]

Originally posted by OriginalGoods
the only way it would affect the o2 sensor and throw any codes is if its after the cat, and i doubt it is.



Originally posted by adidas


2 O2 sensors are found on the 1.8T, pre and post cat.

Correct welcome to OBDII


Originally posted by RickDaTuner




:thumbsup:


Holy ass your a knowledgeable tech. I have met techs who couldnt even tell me how a cam phasor worked properly.

[J-hop]

Originally posted by btimbit

If you're worried about the cat, you could just remove it. There are a few ways of preventing a CEL from popping up because of it. You could try a spacer for the post cat 02 sensor; http://store.42draftdesigns.com/O2-Sensor-Spacer_p_306.html

Or you could get some software to delete it entirely.

As mentioned the Cat efficiency can easily be tested with the Vag com software, so do this before mucking about with spacers and software:

http://forums.vwvortex.com/showthread.php?1265064

[crapstixs]

Originally posted by J-hop


As mentioned the Cat efficiency can easily be tested with the Vag com software, so do this before mucking about with spacers and software:

http://forums.vwvortex.com/showthread.php?1265064 you can also check the efficiency in mode 6 with just general global OBDII. you dont need vag com, but it dose make it easier.