Yeah I'd be interested to know as well. My VX ran terribly until I figured and corrected an incorrectly set ignition timing issue. In the process I also got new plugs, wires, 02 sensor. I went from ~33mpg to ~45mpg. Now that I'm at 45mpg, I can't help but wonder why I can't get 50+ mpg, especially since my commute is 70% hwy/30% local.

I'm happy at 45mpg, but I'd be much happier at 50+mpg!

When I purchased my 92 Fed VX a year ago, previous owner warned that he had been unable to get over 38MPG. I was averaging only ~40MPG until I Seafoamed the engine. After Seafoaming, the car made noticeably more power, required less downshifting and my gas millage under real world (less than perfect MPG) conditions has been running 46 - 48 MPG.

Ooo good idea, vxhatch. I'm gonna try that this weekend.

Keep 'em coming guys!

What was the mileage on your VX?

We have a very expensive and finicky o2 sensor and I have to wonder what impact the Seafoam product would have on it.

No, they should not "nail" 50 to 60 mpg freeway. Mid forties is more like it. People like to report inflated numbers.

Your fuel economy will taper off as the engine gets older. Most VX's are in the 200k range by now and haven't necessarily been well taken care of. The piston rings wear and don't seal as well. Compression is uneven. Grease and carbon build up inside the motor and on the sensors.

Soaking your injectors doesn't do anything. At the very least you should have someone pulse them (connect wires to the pins and rapidly tap them to a battery careful not to burn them up) while you squirt them. But for a little over a hundred bucks you can have them balanced and blueprinted properly and they will be better than brand new.

It was 112k when purchased and ~125k when seafoamed. I too was concerned about the Seafoam damaging the O2, so I removed it during the cleansing process. I just left the port open, but I understand a spark plug will screw in fine to plug the hole during the seafoaming. BTW, I never replaced the O2, but my FE seems good and I can feel the car coming out of lean burn, so I think I'm set.

hmmm...you mis-quoted me, I said 50mpg @60 miles per hour, "not 50-60mpg." I think there are several credible members getting 50mpg at conservative highway speeds.

Regarding fuel injector cleaning https://www.witchhunter.com/ is both top of the line service and value priced @ $18 per injector. I can highly recommend.

Agreed that a neglected engine is going to suffer. I don't think that applies to mine as I have thick files from the one prior owner.

I believe you about the buildup, that's going to have an effect. vxhatch's experience with Seafoam is telling. Seafoam's website lists three ways to add the product to the engine, (1. through direct manifold vacuum line, 2. into oil crank case and 3. into fuel tank) What did you do?

madpup, please let us know if your "seafoaming" has similar positive results.

What freeway can you safely drive 60mph on? Maybe at 3AM... more and more hypermiling just sounds dangerous and stupid.

Pour 1/3 into the gas tank, 1/3 into your oil, and suck 1/3 in through your brake booster hose slowly enough not to stall it. Follow the directions. Change your oil and filter with the oil nice and hot.

Besides doing that you'll need to remove and clean your IACV, PCV throttle body, and intake manifold. They will need new gaskets. The IACV and throttle body can be taken care of with lots of carb cleaner, some rags, and compressed air if you got it. But for the manifold you'll need to have someone clean it out with a parts washer. And on the VX you'll also need to clean the EGR.

I poured 1/3 into the a full gas tank. After the tank was depleted, I poured 1/3 can into the crankcase and drove ~ 80 miles. That evening I did the fun one, 1/3 into the booster vac line, a little at a time w/ the O2 sensor removed. Billowing white smoke, big fun! I also sprayed Seafoam Deep Creep into the intake manifold for good measure; somewhat loosely following these directions.

Fresh oil change and done.

Oh, and I'm not a hypermiler; though I do go gentle on the gas and keep it under 70 MPH most of the time. My gaslog primarily represents my 80-mile RT commute that includes DC rush-hour traffic.