Alfa Romeo Giulia Forum banner
1 - 20 of 97 Posts

·
Registered
Joined
·
43 Posts
Discussion Starter · #1 · (Edited)
I'm asking because when I checked the specs in the "Featured vehicle" window on the right of this page, I saw where the requirement was for regular fuel. Is that true? I think it may be an error. The specs are listed by
AutoGuide.com here: http://www.autoguide.com/new-cars/2017/alfa-romeo/giulia/index.html
Flyby out
EDIT: AlfaRomeoUSA lists the octane requirement as "regular unleaded 91 octane". It's a bit confusing to me to see 91 octane listed as "reqular", which in my area is either 89 or 87 octane. Also here, 91 octane carries a "premium" price. See here: https://www.alfaromeousa.com/content/dam/alfausa/pdf/giulia-quadrifoglio/2017_AR_Giulia_SP.PDF
Now I wonder how many of you use 93 octane in your 2-liter turbo. :)
 

·
Registered
Joined
·
359 Posts
I specifically asked our salesman this, and pointed out how confusing the Alfa Romeo language was on it.

He was absolutely adamant, 91 octane required on the 2.0L Turbo.
 

·
Vendor
Joined
·
619 Posts
91 or better on these cars!
 
  • Like
Reactions: JuliaQ4-Nut

·
Registered
Joined
·
576 Posts
Shell 93 gents.....with these direct injection turbo motors...
Agreed! If available, always spring for the highest octane for piece of mind. What's cost differential anyway?
 
  • Like
Reactions: alfa55

·
Registered
Joined
·
43 Posts
Discussion Starter · #7 · (Edited)
Shell 93 gents.....with these direct injection turbo motors...
The nature of direct-injection engines is that fuel is sprayed directly into the cylinder. That's great for improved efficiency and a bit of charge cooling. Then again, with direct-injection engines, it's the valves that suffer from carbon build up. See here: Note the mention of the "Italian tune-up". :) VW specs "Top-tier fuel for my Golf-R. That's great for what goes on inside the cylinder, but again the valves (stems and seats don't benefit from the extra cleaning additives found in those fuels because the fuel spray does not touch them (to clean off carbon-build-up). Perhaps Alfa Romeo can suggest an appropriate aftermarket oil catch-can? I use Costco fuel in my car. It's 93-octane, and is listed as a "top-tier" fuel.
Flyby out
 

·
Registered
Joined
·
5,020 Posts
The nature of direct-injection engines is that fuel is sprayed directly into the cylinder. That's great for improved efficiency and a bit of charge cooling. Then again, with direct-injection engines, it's the valves that suffer from carbon build up. See here: https://www.youtube.com/watch?v=RnhUJsZXzmg&t=71s
Note the mention of the "Italian tune-up". :) VW specs "Top-tier fuel for my Golf-R. That's great for what goes on inside the cylinder, but again the valves (stems and seats don't benefit from the extra cleaning additives found in those fuels because the fuel spray does not touch them (to clean off carbon-build-up). Perhaps Alfa Romeo can suggest an appropriate aftermarket oil catch-can? I use Costco fuel in my car. It's 93-octane, and is listed as a "top-tier" fuel.
Flyby out
that's the point...using a "top-tier" gas product "should" help with CB....though you do need to wring these beasts out every now and then....
I also treat my rides to Techron by Chevron....yeah yeah yeah I know supposedly BS....but I have personally seen what the stuff can do...(tear down of my S50B30)....my wrench called me out of work to go see...:D I was shocked..in a good way
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #9 ·
that's the point...using a "top-tier" gas product "should" help with CB....though you do need to wring these beasts out every now and then....
I also treat my rides to Techron by Chevron....yeah yeah yeah I know supposedly BS....but I have personally seen what the stuff can do...(tear down of my S50B30)....my wrench called me out of work to go see...:D I was shocked..in a good way
Seems an impressive result. Techron? I'll look into it.
thanks!
Flyby out
 

·
Registered
2020 Alfa Romeo Giulia Sport Ti AWD
Joined
·
7,473 Posts
Octane choices where I live are 87, 89, and 93. Guess I have to go top shelf.
And watch out for ethanol. The manual says 0-15%, so no E85 for Giulia.

Has anyone inadvertently filled up with 87? If so, how did the engine react?
 

·
Registered
2018 Q4 with Fiamenghi Ti exhaust, Race Mod, and Tecnico wheels.
Joined
·
7,734 Posts
Octane choices where I live are 87, 89, and 93. Guess I have to go top shelf.
And watch out for ethanol. The manual says 0-15%, so no E85 for Giulia.
In the Silicon valley area the standard grades are 87, 89, and 91. Not all stations have 91.
In the Bridgeport, Ca area (far eastern California) anything other than 87 is often unavailable. OTOH, the 60 mile drive to Nevada will yield 91 octane at $1/gallon LESS than in Bridgeport.

Then there are these guys offering up to 101 ("only" $6.90/gallon):
https://www.yelp.com/biz_photos/sunol-super-gasoline-sunol

Anyway, it seems like the main culprits regarding CB is oil from the PCV and simply not getting the combustion chamber hot enough to burn the carbon out. All hail the Italian tune up! Use top tier oil in the engine only. Install an oil separator in the PCV path IF your local smog agency allows it and you can find one. CARB would not allow me to add a PCV to my diesel truck (a complicated system with an oil separator) even though it makes the machine much cleaner, because it is not "approved" equipment.
 

·
Registered
Joined
·
2,988 Posts
If 93 was available here, I'd be using 93. But the best we get is 91...

I'm sure that the ECU can de-tune the engine if it senses ping or knock (per-detenation). In a pinch a lower grade fuel should work, you just won't get the performance or the mileage as with the higher octane.
 

·
Registered
Joined
·
57 Posts
Fuel choice has little to do with carbon buildup. CB is mostly a design issue: the product of oily gases recirculating (EGR) into the intake, with no wash effect from the fuel as you would get with port injection. Extra additives may help keep injectors free of varnish etc, but ultimately if CB is a problem, there's nothing that can be done except (a) periodic dismantling and cleaning and/or (b) modifications to the design, e.g. a catch can in the breather system.

My Alfa direct injection engine :) :

 

·
Registered
2018 Q4 with Fiamenghi Ti exhaust, Race Mod, and Tecnico wheels.
Joined
·
7,734 Posts
Fuel choice has little to do with carbon buildup. CB is mostly a design issue: the product of oily gases recirculating (EGR) into the intake, with no wash effect from the fuel as you would get with port injection. Extra additives may help keep injectors free of varnish etc, but ultimately if CB is a problem, there's nothing that can be done except (a) periodic dismantling and cleaning and/or (b) modifications to the design, e.g. a catch can in the breather system.

My Alfa direct injection engine :) :
How many miles on that engine?

Anyway, I doubt that there is much oil residue in EGR (Exhaust Gas Recirculation) gases and the problem is in the PCV (Positive Crankcase Ventilation) gases.

For my diesel truck, the PCV system that I fitted before California started smog testing diesels consists of a one way PCV valve, a large filter (10" diameter, 3" thick) on the intake manifold and an oil return line connected back to the crankcase. The filter has a venturi in the middle which makes the intake air flow create a negative pressure that helps draw out the crankcase gases. This system was designed for the marine version of this engine, so that it won't explode when the engine is installed in an enclosed boat hold. I installed it on my truck because I was tired of the blow-by getting sucked in by the truck's interior ventilation system. I expect that something of similar complexity is needed on a gas engine to remove the oil from the gases.

Without the PCV system, my truck has a breather system that consists of a short hose that terminates in a catch cup. This will collect several ounces of oil between oil changes (7500 miles) and is supposed to be emptied with each oil change. Assuming high performance gas engine blow-by is similar in content (compression ratio is similar, Giulia has more turbo boost), it is easy to understand this carbon buildup issue.
 

·
Registered
Joined
·
57 Posts
I think 110k miles on that engine at that point, although the previous owner had it rebuilt to some unknown extent at 54k after a cambelt snap. It still ran fine, if not optimally.

When I say EGR, I mean PCV breather too. Actual EGR on it is internal, via cam overlap, and it burnt oil - a litre per 1000km was considered normal for the type.

I do agree with your PCV assessment though. I expect it would reduce but not eliminate the issue.
 

·
Vendor
Joined
·
619 Posts
You purchased/leased/financed a car valued at 40k+...put the best fuel you can in the car.

91/93/94oct
 

·
Registered
2018 Q4 with Fiamenghi Ti exhaust, Race Mod, and Tecnico wheels.
Joined
·
7,734 Posts
You purchased/leased/financed a car valued at 40k+...put the best fuel you can in the car.

91/93/94oct
I've got Jeffrey Pines (Pinus Jeffreyi) on my property. The turpentine is rated 0 octane (by the definition of 0 octane). Perhaps not a suitable source for fuel...
Several 19th century turpentine factories exploded before they figured this out.

I don't think any refineries in Northern California are producing anything better than 91 octane. I presume that the rare station that has better fuel has imported it or supplemented it, accounting for the silly high prices <sigh>.
 

·
Registered
Joined
·
787 Posts
Here in the midwest I get 91 pure gas with no ethanol. I'll start it, ethanol has less energy than gas therefore less mpg and maybe power (big debate on power and compression in street vs racing engines).
 
1 - 20 of 97 Posts
Top