Fuel system cleaner

[Dusty Bones 8]

Noticed the manual says to run a fuel system cleaner every now and then. Most new car manuals instruct you to never use anything but no one ever listens.

Of course the manual says use genuine GM part number XXXXXXX and we all know it's just a sales pitch. So after I changed the oil I dumped in a can of what I've used forever. Ran it to near empty before filling up again. Next five fill ups I average 3.6mpg more. I bought it "used" with just over 6,000 miles on it.

I think whoever had it before me was shifting (manual trans) when the shift light says to and lugged the ever living life out of it. Lugging is a sure fire way to build up carbon everywhere. I'm not sure if it was switching to real oil or the cleaner or a combo of the two but it runs much smoother now.

This thing saves me over $200.00 a month in gas alone. Practically pays for itself. It's an amazing little car and the engine makes the least amount of noise of anything I've driven. I like the auto headlights too. Now all I need to do is put a train horn on it.

[Retired old Gearhead 201]

That's interesting info..Fuel system really should not need cleaning very often and although the 'lugging' may have built up some minor carbon deposits, the affected parts would be the very hot areas such as the valve & lower cylinder head area rather than fuel jet nozzles or other fuel delivery components. The only way to get an accurate fuel usage comparison is to drive the same stretch for the same distance at the same speed at the same temp.(cruise) resetting the 'average' each time..however if you find it makes a difference in most conditions..It's probably working. Not a bad idea to do as you did every once in a while. Glad you like the car..I find it's best feature is small size, 'sporty' handling and being able to park and move where slightly bigger cars can't....'Nuff said...

[Dusty Bones 8]

It only gets driven to work and back. Same route, same pump, temps were 20-40F. Fill ups were within 4 miles of each other at time of fill up and that was dependent on if I filled up on the way home or on the way in.

the only two changes were oil and fuel system cleaner.

[Skids 108]

I threw in a bottle not to long after I got mine new and it seemed to help a bunch too . my thinking was just old shitty gas from korea sitting in it for so long just clean out all the crud from it (maybe they have good gas over there, i don't know but i doubt theyre as stringent on clean burning and all that compered to california and top tier gas blah blah plus it was probably sitting in there for months) but it jumped in acceleration and mpgs. I do it now and doesnt really seem to make as huge of an improvement as it did that first time probably because of the cleaner burning gas here..?? who knows

[Dusty Bones 8]

I threw in a bottle not to long after I got mine new and it seemed to help a bunch too . my thinking was just old shitty gas from korea sitting in it for so long just clean out all the crud from it (maybe they have good gas over there, i don't know but i doubt theyre as stringent on clean burning and all that compered to california and top tier gas blah blah plus it was probably sitting in there for months) but it jumped in acceleration and mpgs. I do it now and doesnt really seem to make as huge of an improvement as it did that first time probably because of the cleaner burning gas here..?? who knows

The thing with mine was 6,000 miles in two years from the first owner. I don't think they had it over 45 when they had it and only drove 3,000 miles a year. That shift light will fool ya if you haven't driven a stick before or just blindly trust it. I gather in the name of saving gas they (GM) prefer you to lug it and dirty it up quick.

On another note, when I got my Harley some years ago it only had a bit over 1,000 miles on it and it's almost mandatory to lug them things. People cruise at way too low of an RPM on them things. When I went through it I pulled the plugs and the tops of the Pistons were caked in carbon. Was for sure lugged its entire life. All I did was ride it at less carbon building RPMs with no cleaner at all and by 3,000 miles I could see metal on the tops of the Pistons. If I would have used a cleaner it would have broke off huge chunks. It was BAD! Same probably would have happened with the spark. I guess it was worse than normal in my case. So the cleaner helped quicker.

It's probably worse in a auto trans where you don't have a choice of rpm to cruise at. Chevrolet knows it and it has to be the reason they say use a fuel system cleaner. Otherwise it would read like other manuals to never use an additive in the gas.

Just a heads up for everyone. Your spark may benefit from a good fuel system clean. Last gas up on Monday, mileage is at 44.6mpg actual, not the dash read out. Mostly rural 55-60 and a little city just before I get to work. The truck it replaced was getting 14-16mpg. I'm saving huge in gas now.

Edited February 3, 2016 by Dusty Bones

[Retired old Gearhead 201]

[Clipped].......It's probably worse in a auto trans where you don't have a choice of rpm to cruise at. Chevrolet knows it and it has to be the reason they say use a fuel system cleaner. Otherwise it would read like other manuals to never use an additive in the gas.

Just a heads up for everyone. Your spark may benefit from a good fuel system clean. Last gas up on Monday, mileage is at 44.6mpg actual, not the dash read out. Mostly rural 55-60 and a little city just before I get to work. The truck it replaced was getting 14-16mpg. I'm saving huge in gas now.

You make a good point that never crossed my mind...I have the '13-4speed auto tranny and it runs at significantly higher RPM at speed than the CVT units..also I am constantly booting it to down shift and cruise at high RPM's as I know that doing that keeps things clean and that's the way I always drive my cars...fast and hard. So you make a good point for people to use the additive if they don't do many high RPM runs. Also using a 10% ethanol blend gas is a good way to keep the valves, plugs and lower cyl head clean. My mechanic has a little display in the waiting area of various car parts cut open to show various conditions and one of those is a side by side comparison of two 4 cyl DOHC heads at about 150Kmi useage. One used regular no ethanol gas and the other 10% Ethanol. The Ethanol head was very clean and the other not so much.. I think that Ethanol is now in most gas, particularly in winter as it acts as gas-line antifreeze as well. The displayed heads were from a time when Ethanol was not widely used and only certain stations offered it. I think your "heads up" is a valid point.

[sparkfanatic 70]

My 13 Spark manual recommends using top tier gasoline . The additives are only recommended if you don't use that type of fuel . I always use top tier in all my cars . You can look up which brands of gas have that extra detergent on the top tier website .

[Dusty Bones 8]

My 13 Spark manual recommends using top tier gasoline . The additives are only recommended if you don't use that type of fuel . I always use top tier in all my cars . You can look up which brands of gas have that extra detergent on the top tier website .

Top tier does keep it clean. I live way out and closest top tier to me is 16 miles away. For some it's not readily available.

I've also witnessed nothing but top tier fuels being used carbon up engines when they were lugged consistently in any kind of engine. So the use of top tier alone will not guarantee a nice clean engine if driven in grandpa mode or a few miles here and there without ever getting fully warmed up.

My generator runs at 3600rpm constantly and after hundreds of hours there was barely a spec of carbon anywhere when I tore it down. That thing burns nothing but nasty old gas too.

[sparkfanatic 70]

There's probably a lot of factors involved . None of my street cars are ever driven hard , in fact rarely over posted speed limits . These range from economy 4cyl like the Spark to high reving performance 4cyl mated to an auto Trans and a Pontiac with a larger high torque 4 cyl that I drive now probably no more than 5 miles over a few weeks period . Both the Pontiac and Nissan are 20 years or older . None of them has had any fuel related issues and all drive like the day I bought them and only the Nissan had a fuel cleaning back at 30K mile service many years ago . This was part of the dealers 30K service not because of any issue . I do maintain all my cars probably at 50 % early service intervals including fuel filters on those cars that have replaceable ones . I never use cheap gas and stick to top tier all the time refueling at around 3/4 of tank so I never put in more than a few gallons at a time . I do everything to avoid getting large quantities of contaminated fuel or condensation in the tank .

[Retired old Gearhead 201]

Another thing you can do with the very low gas prices today is run the premium xx octane once in a while, not because of the octane, but because they have more cleaning agents in them..check the label on the pump handle to get the right one. Both Shell and a few others offer that product.

[Dusty Bones 8]

Another thing you can do with the very low gas prices today is run the premium xx octane once in a while, not because of the octane, but because they have more cleaning agents in them..check the label on the pump handle to get the right one. Both Shell and a few others offer that product.

Last year I was reading an actual test where non top tier gas was compared to top tier. The level of detergents in non top tier premium was at best half that of top tier regular grade. So an off brand premium won't even be half as good as top tier regular.

I know the current aveo the wife drives and remember the 05 run and ran best on BP. I'm going to go out of my way and run BP from now on. It will be worth it, might be out of the way but I can live with that. I can only guess but the first owner had to be running some pretty crappy gas and only doing very short drives.

Running a fuel cleaner from now on should be a once a year or more thing from now on. I'm not really wanting to deal with cleaning out cruddy gas crud just because the stations are closer to home.