My mpg has dropped off. When brand new, car got 32-33 commuting. Then it went to 30. Now I am getting 25-27. If I set the cruise at 56 I can eek out 29. Car has 153K miles on it. New plugs. I usually run WaWa gas. Do any of the over the counter "dump it in the tank" cleaners actually work? How about the auto shop cleaners? Any other ideas on what I can do to up my mpg (other than slowing down)?

My mpg has dropped off. When brand new, car got 32-33 commuting. Then it went to 30. Now I am getting 25-27. If I set the cruise at 56 I can eek out 29. Car has 153K miles on it. New plugs. I usually run WaWa gas. Do any of the over the counter "dump it in the tank" cleaners actually work? How about the auto shop cleaners? Any other ideas on what I can do to up my mpg (other than slowing down)?

20" chrome wheels?:lol:

Aircleaner, all anti pollution stuff, higher tire pressure.

20" chrome wheels?:lol:

Aircleaner, all anti pollution stuff, higher tire pressure.:yeahthat: That filter in the anti-pollution BS, but usually you'll get the light for that if it's clogged.

Fords have always sucked on gas mileage...:ohwell:....but they last longer than Chevy's....:lol:

If you're going to try any of the off the shelf products, use Sea Foam. You WILL notice an improvement right away, but that's just due to the product itself. If the performance gain doesn't last after that tankfull, you probably need more serious cleaning. I would suspect tho, that the loss of fuel mileage is less the injectors and more other factors, like engine age.

There are some self-help videos on youtube for removing and cleaning injectors. Not as efficient as a $3000-5000 shop machine can do it.

I wanted to replace the injectors in my GMC truck. $100 a pop x 8. I run a can of Sea Foam every couple of tanks instead.

If you're going to try any of the off the shelf products, use Sea Foam. You WILL notice an improvement right away, but that's just due to the product itself. If the performance gain doesn't last after that tankfull, you probably need more serious cleaning. I would suspect tho, that the loss of fuel mileage is less the injectors and more other factors, like engine age.

There are some self-help videos on youtube for removing and cleaning injectors. Not as efficient as a $3000-5000 shop machine can do it.

I wanted to replace the injectors in my GMC truck. $100 a pop x 8. I run a can of Sea Foam every couple of tanks instead.I figure some of it is the ethanol in the fuel (I've heard a claim of 10% cut in mpg due to it), engine age and dirty injectors. Will try the sea foam. It's still better than the Suburban gets...

Another thing to do is jhave a qualified shop check the calibration/output of the sensors that are critical to the injector firing pulse width in the first place; they can be out of calibration enough to affect your gas mileage but still within the limits that preclude setting a code that will turn on your CEL.

O2 sensor(s), Mass-Air sensor, BAP sensor, IAT and coolant temp..those are the ones that the ECM uses to determine where you are on the fuel map and how that value needs to be modiifed to achieve target AF ratio. The O2 is arguably the most critical of all of them as far as affecting your mileage.

Gilligan, those should pop a CEL, though, if they are far enough out. Gives some timeframes that the drops have happened. If tyhis latest drop is since fall, then I might pin it on winter gas. The addiitve package changes, and the winter package lessens MPG. My car drops 1.5-2mpg in the winter over the summer.

Also, and this might sound silly, but you have kept up on your tire pressures, correct? If they were filled to 32 psi after driving 4-5 miles back in August, they are pretty low when the temp is in the 40-50s. Figure roughly 1psi per 10 degrees, and tires that were at 100F when filled to 32psi are sitting at 26psi when cold at 40F, and only get back up to at best 30 when driving.

I check my tires regularly. I usually run 42-44 PSI. Sticker on door calls for 32, but the tires are rated for 44, so that's where I try to keep them.

Air filter is the factory "non-replaceable" unit.

If you are running 42 set hot, then your are really running them over max pressure. You are still not really dangerous, given engineering margins of safety, but I think that might be pushing them more than you need.

In any case, that's not your issue with MPG. Overinflation can have negative effects on handling and tire wear, but it shouldnt affect MPG in a bad way.

I figure some of it is the ethanol in the fuel (I've heard a claim of 10% cut in mpg due to it), engine age and dirty injectors. Will try the sea foam. It's still better than the Suburban gets...

I had a '64 Jeep Wagonneer. 350ci (or thereabouts) with a 4 bbl carb and beach tires. 8mpg on the highway. But that was also back when gas was under 50 cents a gallon.

Gilligan, those should pop a CEL, though, if they are far enough out. .

No indeed..the valid range of the O2 sensor is quite wide, yet it only needs to be out of calibration a few percent to make a noticeable difference in fuel consumption.

The error testing and thresholds that throw a CEL are pretty crude; something has to be really wrong to create a signal that far out of range.

I build custom EFI setups...including the customization tuning of the ECMs that go with. Current project is multi-port EFI setup on a supercharged....1949 Ford flathead V-8.

I figure some of it is the ethanol in the fuel (I've heard a claim of 10% cut in mpg due to it), engine age and dirty injectors. Will try the sea foam. It's still better than the Suburban gets...

And winter gas has additives that drop your MPG even more (from what I understand).

Also if you gas up in Calvert they get hit with the Metro fuel mix additives that produce less smog.

I figure some of it is the ethanol in the fuel (I've heard a claim of 10% cut in mpg due to it), engine age and dirty injectors. Will try the sea foam. It's still better than the Suburban gets...
Everything I own that burns gas has lost mpg in the last couple of months. Both Shell and Wawa went down in mpg at the same time???? I think we're being hoodwinked about the ethanol. Besides hurting fuel usage, ethanol can really screw up an engine not designed for it.

I wanted to replace the injectors in my GMC truck. $100 a pop x 8. I run a can of Sea Foam every couple of tanks instead.

100.00 is pretty cheap for an injector. Where did you get the price from?

Everything I own that burns gas has lost mpg in the last couple of months. Both Shell and Wawa went down in mpg at the same time???? I think we're being hoodwinked about the ethanol. Besides hurting fuel usage, ethanol can really screw up an engine not designed for it.

I wonder if anyone has even done a calculation if you could decrease everyone's MPG by say 10% how mucn more tax revenue the state will take in increased gas sales..

Add a little addtiive that makes the gas less efficient (probabaly on a fraction of a cent per gallon) and increas revenue by millions..

I wonder if anyone has even done a calculation if you could decrease everyone's MPG by say 10% how mucn more tax revenue the state will take in increased gas sales..

Add a little addtiive that makes the gas less efficient (probabaly on a fraction of a cent per gallon) and increas revenue by millions..

I've seen a couple different tech articles that analyzed and discussed the (detrimental) effects of ethanol and other additives on engine efficiency or fuel consumption. I'd have to google search to find them again..but they are out there.

100.00 is pretty cheap for an injector. Where did you get the price from?

Advance Auto. $97 each. I just could not see spending over $800 for injectors that *might* improve the performance.

Part # 67166

I've seen a couple different tech articles that analyzed and discussed the (detrimental) effects of ethanol and other additives on engine efficiency or fuel consumption. I'd have to google search to find them again..but they are out there.

I find it interesting that NASCAR is now advertising that they use an alcohol blend. Also interesting that more motors have blown up recently than I remember seeing previously, but haven't heard one word or complaint from any team owner or driver. It's like they are being paid to shut up about it.

I find it interesting that NASCAR is now advertising that they use an alcohol blend. Also interesting that more motors have blown up recently than I remember seeing previously, but haven't heard one word or complaint from any team owner or driver. It's like they are being paid to shut up about it.
Alcohol is a good race fuel if the fuel management is programmed for it. If the engine is carbureted, the main jets have to be drilled way out. The more alcohol you use, the worse the mpg. I'm surprised about NASCAR since pit stops, or lack of, is so important.

Alcohol is a good race fuel if the fuel management is programmed for it. If the engine is carbureted, the main jets have to be drilled way out. The more alcohol you use, the worse the mpg. I'm surprised about NASCAR since pit stops, or lack of, is so important.

Because of a couple factors, the biggest simply being what you mentioned regarding the fuel volumetric flow rate increasing so much, alcohol results in cooler combustion chamber temps for the same HP as gasoline. So alcohol fuel inhibits piston meltdowns.

That and alcohol has intrinsically a higher effective 'octane' rating too.

Advance Auto. $97 each. I just could not see spending over $800 for injectors that *might* improve the performance.

Part # 67166

Cheapest I found mine were from 350 to 400 each.

I've seen a couple different tech articles that analyzed and discussed the (detrimental) effects of ethanol and other additives on engine efficiency or fuel consumption. I'd have to google search to find them again..but they are out there.

mostly the seals and rings that are eaten up by it right?

Because of a couple factors, the biggest simply being what you mentioned regarding the fuel volumetric flow rate increasing so much, alcohol results in cooler combustion chamber temps for the same HP as gasoline. So alcohol fuel inhibits piston meltdowns.

That and alcohol has intrinsically a higher effective 'octane' rating too.

I was always led to believe that the more alcohol you put in the fuel, the more damage you can do to the motor, meltdown aside. And I'm not referring to the plastic carb parts and such, thinking more of increased piston and valve blow-by and wash down.

I'll have to do some more research on that.

Cheapest I found mine were from 350 to 400 each.

Diesel vs gas? :shrug:

I was always led to believe that the more alcohol you put in the fuel, the more damage you can do to the motor, meltdown aside. And I'm not referring to the plastic carb parts and such, thinking more of increased piston and valve blow-by and wash down.

I'll have to do some more research on that.


Not that I've ever noticed..and I've run alcohol-fueled 'race' engines (BB Fords) for years in mud boggers and the odd boat. Of course, lets face it..we are not talking about 'long lived' engines in that case either.

Diesel vs gas? :shrug:

I guess, other than the rail pressure I dont see that much difference in them

Advance Auto. $97 each. I just could not see spending over $800 for injectors that *might* improve the performance.

Part # 67166You can also have your stock injectors serviced and tested considerably cheaper.
Fuel Injector Cleaning and Testing (http://www.cruzinperformance.com/fuelinj.html)

You can also have your stock injectors serviced and tested considerably cheaper.
Fuel Injector Cleaning and Testing (http://www.cruzinperformance.com/fuelinj.html)

Also a good option. However, it had better be same-day turnaround or I'd have to buy new ones anyway! Don't think I could be without my primary vehicle waiting on a mail-order process.

I'm sure there are some places local that could do that.

My mpg has dropped off. When brand new, car got 32-33 commuting. Then it went to 30. Now I am getting 25-27. If I set the cruise at 56 I can eek out 29. Car has 153K miles on it. New plugs. I usually run WaWa gas. Do any of the over the counter "dump it in the tank" cleaners actually work? How about the auto shop cleaners? Any other ideas on what I can do to up my mpg (other than slowing down)?


BG 44K...Run it down to about a 1/4 tank, add 1 can and run it till almost empty, fill-up
with "real" gas and add another can. If its an injector problem you will see a difference before your next fill-up.

BG 44K...Run it down to about a 1/4 tank, add 1 can and run it till almost empty, fill-up
with "real" gas and add another can. If its an injector problem you will see a difference before your next fill-up.
I'm guessing that this is the banged up vehicle and probably no longer an issue.

I'm guessing that this is the banged up vehicle and probably no longer an issue.

Try "Lucas" brand injector cleaner at Auto Zone. I usually put some in every 5000 miles or so. Keeps my mileage up there.
I have also noticed the drop in mileage between the Ethanol mix and gas.

This warm weather has put my mpg back up where it should be.

I'm guessing that this is the banged up vehicle and probably no longer an issue.
True, original question was in regards to my dear departed Focus. However, with 2 other vehicles with 100K plus miles, they can proabably stand a cleaning too.