moribundman

I swear there is a noticeable power gain over the hotter UFX7.9.

This means I'm done experimenting with spark plugs. All in all I'd recommend the OEM NGK BKUR6ET10 as the best all-around choice. If you drive like a nut (me), if your fuel is sub-standard, or if your engine makes more horses than stock, you may feel the Beru UFX5.6 will give you a marginal edge in performance. I can't yet comment on the longevity of the Beru spark plugs.

I also used one bottle of Techron injector cleaner for one tank before I switched the spark plugs. I wanted to see if the Beru plugs would show the same fouling I got when using Techron with the Bosch +4 spark plugs last year. I saw no signs of any fouling in case of the Beru spark plugs. I give Techron a thumbs up for use with the Beru plugs.

AlwaysAudi

good to know about the beru 5/6, I just could not find them....Maybe I didn't look hard enough. I figured the Denso's run cold so they should serve the same purpose.
And I don't think your crazy about the gain, I definitely thought I could tell a difference. when I went from my 4+ to the Denso...but then again my 4+ were SHOT.

TropicGreen

Any time you change maintenance items, the engine will tend to run better, so that is probably why you felt a difference in power. It just brought the performance back up to what it should be.

At least, that is what I think probably happened.

euromotorsports

Where did you buy them at and how much for the Beru Ultra-X 5.6

moribundman

If you had been on this forum a few months ago, you would have seen my thread in which I mentioned that I perceived a distinct power drop when I switched from the UFX5.6 to the UFX 7.9. Meaning your theory holds no water.

Also, since Beru recommends the UFX7.9 for cars running on Euro-gas, it makes sense that the colder plug will perform better with the lower quality US fuel.

moribundman

Local shop, about $8 per plug, if I remember correctly

moribundman

The UFX7.9 is a hair smoother and. while the UFX5.6 results in slightly higher RPM and a slightly "throaty" sound. The engine pulls noticeably harder with the UFX5.6. Fuel economy, or rather lack thereof, seems unaffected.

AlwaysAudi

I don't know what the difference is but with the new plugs in almost exactly at 4k RPM it's like I get a shot. At first I thought it was my Gas pedal since I generally shift right around 4k and as I would get ready to shift there is a boost, and not one I could achieve by stepping on the gas either. I'm guessing it is the cross over kicking but such a noticible difference??? what do you think???...and nothingis blocking/hindering the throttle linkage.

moribundman

... the motor seems a bit more responsive with less lag when I step on it.

The kick you feel must be the intake manifold switchover occuring. When driving sporty, I shift way above, when driving lame, I shift before that point

AlwaysAudi

So I don't have a vacuum hose problem, thats the way she is huh.