It could be the cold weather, but I am currently running on a tank of gas that is fully treated with Techron concentrate plus and it seems I am getting lousy gas mileage. Could the fuel cleaner possibly be the cause?

 

What brand and octane of gas are you using, and apron where are you located? When was the last time you replaced your fuel filter?

 

As long as you stuck to the dosage recommended. Techron will have zero effect on gas mileage. In fact might improve it if you had dirty injectors. Are you sure it's not a tank of winter gas?

 

It's 93 octance, from a generic, but new gas station. What's winter gas?

I was hoping it was related, but I guess not. I have 49,000 miles on the car so I haven't thought about replacing the fuel filter yet. What other maintenance do you recommend to maximize fuel efficiency? Would new air filters help? I have the car in the dealership now for one last warranty check. They are checking my report of the rpm dipping at idle, they said it could be adjusted. I am also have a NYS inspection done. I am hoping when I get it back it will be a little more efficient with the idle adjustment, I dont know.

 

Glyn, is it ok to use those fuel treatment products on our cars? I always thought they weren't recommended.

 

Techron is the only product approved by Benz & Volvo. It is sold as a Benz P/N in some parts of the world.

 

That's the only reason I used it. Otherwise I would have been overwhelmed over the choice of which fuel additive to use.

 

i have the same problem my c350 having 217 mls with the full tank 15 mls\gal i changed the spark plugs and the air filter i don't know where is the problem but i drive 100% in city stop and go so if you can help me and i use only 95 octane from total gas station

 

I've had this happen too. Not with the Benz but rather my Jeep. I used the techron stuff and I got crappy gas mileage.

 

Techron is fine and we use it on all our cars. But, I don't think now is the time to assess a problem. First, let's check the methodology, as you should not be on a "tank of gas", but only a partial tank. You drove to an almost empty tank, added about 10 gallons of fuel to have no more than 12 gallons in the tank in total, and then added Techron? You need to use up the Techron tank, refill to full, and then do the math on the next refill and distance traveled. Then, the actual fuel consumption can be measured.

 

I did that calcilation befor 2 weeks and the same result im having 15 mpg and the full tank betwen 200-220 mile the delar changed the spark plugs and air filter still the same ????
Maybe ill take it to the delar agine and ill pay $$$ agine

 

15 mpg sounds normal since you said earlier that you did 100% city driving.

 

Yes, sounds right to me too, for city stop and go.

 

Ahaa ok thank you