TomsHHR

I must be doing something wrong, I still have the stock plugs at 77K and they are giving the same mileage as they did when they were new 5 years ago.

firemangeorge

Yep.I did that one time.Got a big increase in gas mileage until I realized that I didn't fill it all the way up when I checked it.Found out when I didn,t go as far till the next fillup.Screwed up my numbers since I log every fillup. Just saying.........

Goose2448

I changed my plugs for the first time at 77K and got the same milage up till that point, for the most part. And yes the tank is full, that was the first thing I checked. I also did this on 3 different calculators. I know my math is right, and I know yall dont believe that the plugs make a difference but everything I change plugs in I get better fuel consumption. Even my lawn mower uses less fuel on the E3 plug. Not much but noticable. My suggestion is go with what you feel is best for you. Though I do suggest someone try the Bosh +2's.

Snoopy

If you do a search, IF THE SEARCH FUNCTION WILL GO BACK THAT FAR, several people did try those at that point in time. They didn't get the results that you are expressing. They indicated something like 1-2 MPG increase, which I doubt also. Besides, A REAL MILEAGE TEST would consist of several tanks of gas and the vehicle would be driven over the same course, at the same speeds, with the same stops for the same amount of time, etc. etc.

I believe that was the result for the Nippons and Autolite as well.

Again, read the second, third and fourth paragraph in my post above.....particularly 3 and 4.

Edit....Disregard my statement regarding the search for previous users. My search revealed the Bosch +4 plug was used.

hyperv6

I know it must be the magic beans you taped to the fuel line.

Telepsychic

I'll never use a Bosch plug again. I developed a misfire on #1 and decided to replace the plugs about 25K miles early. Upon removing the #1 plug, a long sliver of the ceramic insulator broke off and fell INSIDE my engine. That was the beginning of a bad couple of days. And yes, I know my way around working on engines and have been changing spark plugs since the '60s. I keep the defective plug on my desk as a reminder. It's a Bosch +2 and I suggest no one EVER use this plug.

843de

I keep it simple, only AC plugs in GM vehicles. Every time I've strayed from that simple rule it has bitten me in the place where I sit. Bosch plugs have a place and that place is in German cars that work well with them. The worst plug disaster I ever had to deal with was caused by Bosch plugs and it was a major expense.

hyperv6

Please to all don't fall for the great promised and crazy gimicks.

Just buy a good name brand plug and just expect good performance. If you want to improve anything go with the platinum tips for longer life.

Plugs only create spark in the path of least resistance and that is all. Simple physics prevent much of the wild claims some like to infer.

Note if any single plug resulted in such great gains ever car built would come with that plug.

Note there is one unexplained issue I do find. Some cars run better on one brand that any other brand. Hondas run best on NGK. Old Chryslers tend to run best on Champion and there are a few others. I tend to think the ignitions on these cars are tuned to the OE plugs resistance and may have something to do with this. This is why often I stay with a OE plug in a stock application.

ImNewHere

I'll never use a Bosch Platinum again. I had one that lost the center electrode in my engine. I had to replace the head and the piston on that cylinder, adn was VERY thankful that it did not score the cylinder wall.

Don06

I was raised on the mantra of "use what the company that built the engine used". I worked at a Ford dealer in 1979 and 1980. We had a customer bring his pickup in with 11,000 miles on it because it was running badly and steered hard. I hooked it up to the scope and found 3 plugs misfiring. I removed the plugs and found Champion plugs in it. Put Motorcraft [Autolite] back in it and it ran fine. Checked the steering and found the king pins were binding. I had to heat them a little to get them to take grease and they freed up. All of the grease fittings were still covered with paint or caps so it had never been greased. The engine had a blue Motorcraft filter on it so it had never been changed because the filters are white and are painted blue when the engine is painted. The owner never serviced his truck but he changed the plugs because he thought Champions would give him more power.

Back in those days, Ford engines only ran on Motorcraft plugs. Some of the drag race guys said that they used Motorcraft plugs in their Chrysler Hemis.

Now Autolite has some plugs that fail in Ford truck and damage the threads in the head.