So the wife filled up the VW with 87 octane

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wemay

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She used my car the other day while I changed the oil on her Hyundai. Being close to "E" she decided to fill'er up. She went to the Mobil station next to our Publix grocery and filled the Passat 2.0T with 87 Octane as per the sticker on the filler door. I gotta tell, I haven't noticed an iota of difference for the 300 miles it's been driven since. Maybe 87 isn't the devil in modern turbocharged sedans calling for it.
 
VW says to use 87 octane. Why use higher octane ? Self-proclaimed experts that think they know better saying it's not good enough ? Pfffft
 
You have technology backing timing down if it hears detonation. I am surprised VW specs a turbo out at 87 octane. All Hyundai turbos spec at 87 I know.
 
My VWs say 87 on the fuel door, that's what they get and they haven't blown up yet.
 
There are cars that require high octane and ones that recommend it.

If its recommended then its your choice to see how it runs on 87.

If it requires it you have no choice.
 
Originally Posted by hallstevenson
VW says to use 87 octane. Why use higher octane ? Self-proclaimed experts that think they know better saying it's not good enough ? Pfffft


The manual says better performance may be had with higher than 87 octane.
 
My current 2.0T recommends premium fuel. They also give the blessing of up to 15% ethanol.

In 17k miles I've used 88octane E15 for the majority of the time and smile all the way to the bank. It does return better mileage than 87E10.

p.s. I also ran 15% ethanol in my GTI...and I was sure to let all the snobs on the forums know!
 
Originally Posted by Quattro Pete
Any noticeable change in fuel economy?


No, I can't say there is. I really thought there would be a drop. Nor has has there been a bump, mind you.
 
So VW built the car you wanted, but they aren't able to tell you what gas it uses?

If built and tuned for 87 Octane higher octane fuel does nothing but waste money.
 
It's worth about 5hp, from the Fifth Gear test years ago. It lets VW advertise a wee bit higher number.

It's tuned for 93, but retards timing when used with perfectly usable 87.
 
I remember a few months ago tests on a few turbo cars and any horsepower difference between 87 and 93. The Honda 1.5 turbo showed almost no difference. the Ford 3.5 had over 20 horsepower difference. The others were very little to a fair amount. Another article has ecoBoost Fords showing a decent increase. Ford recommends the higher octane under certain circumstances. I use it my daughters ecoBoost. Either today or yesterday if my memory is correct an article about LSPI. Higher octane was mentioned as helping decrease the problem but not to a great amount. For me it is worth it.
 
Originally Posted by ammolab
So VW built the car you wanted, but they aren't able to tell you what gas it uses?

If built and tuned for 87 Octane higher octane fuel does nothing but waste money.



Come on, that's just silly...
Again, as I stated before, the manual says the minimum octane recommended is 87, not that the car requires it. It also states that if 87 is recommended, performance may be improved with higher octane.
 
Originally Posted by wemay
Originally Posted by Quattro Pete
Any noticeable change in fuel economy?


No, I can't say there is. I really thought there would be a drop. Nor has has there been a bump, mind you.


Sounds like you owe your wife an apology and a nice dinner.
 
Originally Posted by Brybo86
Originally Posted by wemay
Originally Posted by Quattro Pete
Any noticeable change in fuel economy?


No, I can't say there is. I really thought there would be a drop. Nor has has there been a bump, mind you.


Sounds like you owe your wife an apology and a nice dinner.


She got a great dinner since it was also her birthday weekend .... No apology since I made no fuss over it. She used what the car recommends. I may thank her though, since this may be a new course for me...87 in both turbo'd cars since they both recommend it.
 
Originally Posted by wemay
Originally Posted by ammolab
So VW built the car you wanted, but they aren't able to tell you what gas it uses?

If built and tuned for 87 Octane higher octane fuel does nothing but waste money.



Come on, that's just silly...
Again, as I stated before, the manual says the minimum octane recommended is 87, not that the car requires it. It also states that if 87 is recommended, performance may be improved with higher octane.


That is true. It is quite a subjective matter. It can run 87 octane no problem. But as the owners manual state, with 91 you can see some improvement. That is usually the case with Turbo and GDI engines. At the end of the day, it is your car. One more time, yes, 87 octance is fine.
 
Towing our 7000lb trailer, the eco gets at least mid grade, 89. The rest (90+%) of the time it gets 87. Cant recall ever needing more than half throttle to merge, pass or otherwise beat another vehicle with 87. It pulls HARD when the turbos are spinning.
 
Originally Posted by ammolab
So VW built the car you wanted, but they aren't able to tell you what gas it uses?

If built and tuned for 87 Octane higher octane fuel does nothing but waste money.


Wrong.

In this case the ECU can take the extra octane and advance the timing and change a few other parameters and get slightly better MPGs and performance.
It's enough to make an extra 20-25 cents a gallon worth it, anything more than that it isn't cost effective.

Even VWs made in the mid 1990s could benefit in this way.
 
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