My MPG has Increased

[John H]

I have an 01 auto 4x4 4.0 with 4.10LS and for 4 years or so I've gotten 18-18.5 MPG on the highway and 14 or so in town. I started noticing my mileage go up since last month even city mileage was impressive. The only thing I've done Is stop using seafoam and switch to Gumout multi system tune up. I've used seafoam over 5 years and I've never seen any change to my mileage. I started using Gumout 2-3 months ago so far I think I've used 3-4 cans of the stuff with the last can on a half tank of gas. i used to get 40-45 miles to a 1\4 tank of gas,on this last tank I got 56 miles on a quarter tank. I put 236 miles on this last tank and the gas gauge was still above red. Generally on a full tank I'd usually get 180 to 200 miles and it was on red. I do not work for nor am I affiliated with Gumout, I'm just letting people know my experience with the product and the fact that I see results in fuel mileage vs. fuel mileage results with Seafoam. I have the factory fan with a severe duty fan clutch,stock size 245/75/16 tires,and i haven't cleaned my MAF in over 6 months..yes when using the seafoam I'd clean the MAF at least every 3-6 months in hopes of seeing MPG gains but I didn't. I still have a rough idle that i can not figure out,and no vacuum leaks can be found..I've had the common vacuum leaks in the past

 

[RonD]

Good deal on the MPG increase

Thanks for the anecdote on the reason.

I run fuel injection cleaner once a year in my fuel injected engines, notice a smoother idle after that tank is gone but never noticed much of an increase in MPG.
I have used Gumout, Seafoam and STP, probably a few others as well, lol.

If you are using a cleaner more often in the 4.0l SOHC you could have been causing some pinging/knocking, you won't hear it, this engine has 9.7:1 compression, so to get it to run on 87 octane(regular gas) they had to add a Knock sensor, when a knock is detected computer retards timing, which lowers MPG because it lowers power.
Not sure why Seafoam would cause pinging though, and Gumout would not

 

[Cessus]

Wish I got that milage on my 4.0 ohv. I'm getting 12.5 mpg atm. Driving like a grandpa too.

 

[sgt_apple]

wow that seems like low mpg to me... and the sea foam, what is the point of adding it so frequently? and where were you adding it? i only ask because ive taken a different approach in the past and mileage has been much better than what youve stated with an OHV 4.0

as far as trouble shooting your rough idle is concerned if youve checked and cant find any vacuum leaks and all plugs and coils are functioning properly i would check on the vehicle speed sensor or possibly either the cam position sensor or the crank sensor next

gl

 

[Mickey Bitsko]

Just heard a horror story about seafoam oil additive in a chevy colorado,
It clogged the oil pickup in the pan and fried the relatively new engine, never used it and don't think I will..