STP Fuel Injector Cleaner

[Adam230K]

I saw a thread on this a while ago and i thought i'd give it a go to see if it did anything and i'm astonished.

The Lean codes that i had have now both disappeared and the car is returning more miles to the tank than it ever has. On super unleaded from shell (i'll upload the pic when i get home) it gave me 382miles to the full tank, and this was just going to work and back, so a mixture of A roads and town driving! I tried again this week and on a full tank of normal petrol it gave me 338 miles to the full tank, also no motorways involved.

Prior to this, the best i'd ever seen was 280-300 in town and 330 on motorways. I dont know what the hell this thing has done, but the car is slightly more lively than it used to be, and the occassional dip in performance doesn't seem to happen anymore, and my fuel consumption is actually very good now by any standards, so i'm chuffed!

Anyone car to explain why this could be the case? Clogged injectors?

 

[Adam230K]

Where's Dieselman when you need him

 

[Shude]

330 on motorways is still pretty poor, I usually get over 400 miles to a tank but my journeys tend to be 90% motorways anyway.

 

[johnsco]

Anyone car to explain why this could be the case? Clogged injectors?

Clogged injectors ... Basically YES.
Over a period of usage, the injector nozels get fouled-up.
This spoils the high-pressure spray pattern which should normally give you efficient combustion.
Injector cleaners (STP is one of many) clean the nozels and restore the finely-divided spray pattern.
Combustion efficiency is restored, leading to improved fuel-efficiency and performance.

Glad to hear that STP worked so well.

Cheers.
Johnsco

 

[lynall]

Im not so sure i had my injectors checked recently as i was gaining oil, and the fella said they never see merc injectors ever.

Oh yes and mine were fine 110k.

See what its doing after a couple of tankfuls.

Be wary of the placebo effect ie you know something has been done so even though you think you are not you are in fact driving it differently.



Lynall

 

[Adam230K]

330 on motorways is still pretty poor, I usually get over 400 miles to a tank but my journeys tend to be 90% motorways anyway.

I dont touch motorways at all in my daily commute, so my 330 is good i guess.

 

[lynall]

Compares to mine, does a third more mpg on the motorway ie 22 to 30mpg ish.

Let us know how you get on after a couple of tankfuls as i may try some.


This one? STP Fuel Injector Treatment 250ml from Halfords Price £4.99


Lynall

 

[Adam230K]

Compares to mine, does a third more mpg on the motorway ie 22 to 30mpg ish.

Let us know how you get on after a couple of tankfuls as i may try some.


This one? STP Fuel Injector Treatment 250ml from Halfords Price £4.99


Lynall

Thats the one, i had about 3/4 of a tank and i added the whole bottle to that. And i made sure i thrashed the engine to high revs in that entire tank so it got through

 

[Adam230K]

Ok so i've had quite a long week in terms of travelling and i can report the following:

The first picture is what i got on normal town driving, to and from work, some A/B roads, no motorways, on NORMAL petrol.

The Second picture is what i got on a full tank of Shell V-Power going to coventry, then to birmingham, then to kent, then home, over a period of 3 days (business). So it was pretty much all motorway.

Its quite a huge difference of almost 80 miles, i must also confess that when i did the long trips i was very well-behaved and light footed, sticking to 70 mph. When i drive to work and back, i tend to plant my foot down a few times per trip but no redlining.

Before i did this treatment i was honestly seeing 280-300 in town and 350-380 on motorways, i'm massively impressed with the results and i'm going to use the treatment once more when my car ticks 97k miles.

 

[Shude]

The second pic looks great, I rarely see more than 450 at fill-up time!

 

[lynall]

Ive never seen 450 ever 300 is normalish.



Lynall

 

[vijilants]

Adam,

You are a brave man to let your tank run down to that sort of a level

 

[Shude]

Adam,

You are a brave man to let your tank run down to that sort of a level

What does it mean when I've let mine run down that far and then run out, twice?

The first time it coughed out of juice literally in sight of a petrol station so I had to walk for a couple of minutes and the second time it spluttered up the ramps in the carpark at work and expired in the parking space, had to walk about 1.5 miles to a shell in the rain during my lunch break.

If I filled up at a quarter I'd be at the petrol station every other day though so it feels more efficient to let it run down a bit!

 

[Will]

Actually running dry of fuel is not a smart idea at all. For safety as well as technical reasons it should be avoided.

Will

 

[wemorgan]

Is it advised to change the fuel filter more often if you regularly run the tank very low?

 

[Shude]

Actually running dry of fuel is not a smart idea at all. For safety as well as technical reasons it should be avoided.

What technical reasons are there? The fuel pump thought it was funny to whizz away dry for a few seconds which I didn't think sounded that healthy but otherwise?

 

[Will]

What technical reasons are there? The fuel pump thought it was funny to whizz away dry for a few seconds which I didn't think sounded that healthy but otherwise?

It can't be good for the fuel pump to run dry, but mainly the crud that is lurking at the bottom of the tank can get drawn up and block/contaminate the fuel filters and the rest of your fuel/injection system. Water/sludge/silty type stuff etc.

Even worse on diesel models I believe due to introducing air into the fuel system etc.

Safety-wise it could be quite dangerous to run out of fuel on a public road - should definately be avoided.

Will

 

[Adam230K]

While i do agree with Will, i thought MB tanks where equipped with magnets in certain places to avoid the dangerous sort of filth getting into your fuel system.

I just wouldn't run it dry because i'll need to turn it over for a while til the fuel gets back up into the system and that can be a headache in general.

 

[corned]

...but mainly the crud that is lurking at the bottom of the tank can get drawn up and block/contaminate the fuel filters and the rest of your fuel/injection system.

I have never been persuaded by this argument. It's simple logic. The pickup for the fuel is right at the bottom of the tank to start with, regardless of how much fuel is in there! How else is is going to get all the fuel out? By being positioned half way up the tank? I think not!

This is the real reason why water vapour in diesel tanks is an issue. Water having a higher specific gravity than fuel oil will settle on the bottom, which will then mean it is the first thing which the pump sucks up.

The only crud at the bottom of a fuel tank is the stuff which the gauze filter on the pickup pipe stopped in the first place. Therefore it will continue to be stopped.

 

[Shude]

It can't be good for the fuel pump to run dry, but mainly the crud that is lurking at the bottom of the tank can get drawn up and block/contaminate the fuel filters and the rest of your fuel/injection system. Water/sludge/silty type stuff etc.

I've heard this before but I run my car down to fumes all the time so there shouldn't be any large buildup of the stuff.

It's still a bad idea though and dangerous, both times I ran out I had only left the motorway literally a couple of minutes earlier with the needle resting on the bottom of the gauge.