dirty injectors - necessarily obvious?

[billt460]

Originally Posted By: hatt
Most people don't spend $.60 more a gallon for the heck of it.


I don't either. I want the added performance and knock resistance of the higher octane fuel. But with these newer cars, along with the way they can instantly adapt to changes in octane, it is harder, if not impossible to notice it. I've often wondered what the actual performance change would amount to if you took two identical 5.7 HEMI vehicles. Filled one tank with 87 octane, and the other with 91 octane, what the actual performance difference would be?.. If in fact there was any, it would have to be slight at best, and downright unnoticeable in fact. You would most likely need a dyno to prove anything one way or the other.

In high performance hot rods and race boats, it would become much more obvious. I still use the 91 octane, (assuming I'm actually getting it), because it is much more resistant to knocking. Especially in the extremely hot Summer months we get around these parts. And I really don't drive that much, so the cost is negligible.

 

[hatt]

You're not the only guy that buys gas. Plenty of folks have tunes or carbed performance engines that would let you know in no uncertain terms if you didn't get the proper octane. Clearly it's not something that happens on a routine basis.

 

[ecotourist]

Originally Posted By: Trav
Originally Posted By: ecotourist

….the correct product for the injectors you have is as important as the product being use to get the most effectiveness out of it.

These are a metal pintel style injector with a modified metal pintel cap.

Redline SI-1 is what you want to use in these, use a full bottle to a full tank to start with, next tank a bottle of Berrymans Chemtool then 3 oz per every full tank of SI-1 thereafter. You will probably see an improvement, if not get them cleaned then maintain them or replace them with a modern 4 hole disc style EV1 unit.

Thanks Trav. I'll get on it.

 

[ALS]

I saw a three to four mpg drop in my Volvo 960 over about ten years. Didn't happen at once it was a slow drop off going from 29.5-29.75 down to mid twenty sixes on the highway. I was blaming the E10 for the drop. I always went with the cheapest gas I could find since it takes premium and has a 21.3 gallon gas tank. A buddy of mine who does MPG testing and swears by Shell told me I run a good cleaner through the motor and switch to Shell.

One Sunday I tossed in a bottle of Techron and filled the old girl with with 91-93 Shell V power and went out for a drive.

Two hours later I had to pull over because I thought there was an issue with the motor. The engine was running a little rough when I started and by two hours in, it smoothed out to the point I thought there was something wrong. According to the Scan Gauge no change in fuel mileage for the trip. It was the third tank of Shell V power when I saw the big jump in fuel mileage back up to 29.2 mpg.

The car is my garage queen and exclusive highway car. I noticed the last time I had it out the mileage was dropping again, so it's going to need another bottle of Techron. Obviously this is going to be a once a year preventive maintenance item.

If I run any octane less than 91 the fuel mileage will drop like a rock. I ran 87 once just to see what would happen and my fuel mileage was an abysmal 21 mpg on the highway. 10.7 compression ratio makes 91-93 octane fuel mandatory.

 

[Virtus_Probi]

Originally Posted By: Trav
Originally Posted By: AVB
The state takes that stuff pretty serious here. I don't know how well it is enforced, but there are some large fines to discourage cheating.


I have seen the state taking samples and the city weights and measurements dept checking amounts from gas stations a few times, according to the station owner its regular and random.
I would say they take it seriously.


I always keep an eye out for 93 when I am up in the Whites of NH as it is recommended by Subaru for my FXT and can be hard to find up there...I stopped at one little station I knew in the middle of nowhere and noticed there were 2 and 5 stickers pasted over where the 3 had been for their highest octane fuel.
I would guess they got busted by an inspector...figured 92.5 octane was good enough for me. Subaru actually says 91 is OK, but I still look for 93...they say down to 87 is acceptable (no damage) but the car will probably not run well at that level.

 

[BMWTurboDzl]

Originally Posted By: Trav
Originally Posted By: ecotourist
Originally Posted By: Trav
….the correct product for the injectors you have is as important as the product being use to get the most effectiveness out of it.


@Trav - which type of injectors do I have in my 2000 BMW 528i? (I assume it's the same as US spec.)

Mine has developed a rare and isolated "miss" (a little instantaneous jerk at a steady speed). I've only ever used top tier premium fuel in it but as the car sometimes sits for weeks in bad weather, it wouldn't hurt to run some injector cleaner through it.


Edit to my answer to you. These are your exact injectors. The first picture is when I got them with half of them stripped and blasted the second is all done.







Hey Trav, What do you think of a bottle of Berryman every 40k miles for the BMW N55? I almost exclusively use Costco premium (93) which is upwards 20 cents/gallon cheaper than Shell V-Power (93). The Berryman product appears to be very aggressive.

 

[ecotourist]

Hey Trav, I used the full bottle of Redline SI-1 in a full tank of gas as you suggested and the hesitation is gone. I skipped the Berryman's (I've never seen it around here) and went straight to 3 oz per of SI-1 in every full tank. So far so good.