u guys r going to think im lieing or something... but im going to post this anyway.
i have found that certain products are not all that they seem ive also looked these up on the internet so im including some links along with were i first heard about it

low temp thermostats... they decrease ur gas mileage
they decrease knock by keeping ur car running rich by keeping the pcm in from thinking the car is warmed up yet. i heard this from an ase certified auto tech, he also explained it to me.
http://www.cbsnews.com/stories/2001/...in292951.shtml
*this is apparently a myth

k&n air filters... to oily and come apart after several cleanings
these can destory ur maf from being to oily. they can also destory ur engine if they come apart. i heard this from a gm certified technician
http://www.miata.net/products/intex/knfilt.html
http://autorepair.about.com/library/faqs/bl445h.htm

teflon aka ptfe oil additives... create clogs
this applys to oil additives only. these will clog ur oil filter and oil galleries.
i found out about this when i decided to research oil additives online.
http://www.msgroup.org/TIP043.html
http://www.quickhonda.net/teflon.htm


please take this information into consideration... and correct me were im wrong... and if u have information about other products like the ones listed above please let me know

A 180 thermostat will decrease gas milage if it'* used in the wrong cilmate. If your car never warms up with one then you shouldn't have one in your car. In the right cilmate it helps the engine from getting too heat soaked.

The oil air filters thing is true if the filters are over oiled. otherwise it'* fine

Oil additives? i wouldn't use any.

I have herd the Same thing about the K&N filters from GM. If you are smart and use common sense when cleaning and oiling your filter there will never be a problem with the filter oil even getting close to the MAF

From what I understand this was actually an old myth about the PCM keeping it stuck in open loop, thus not making fuel corrections. The PCM decides to go to closed loop by a number of variables. Including amount of change in temperature (depending on starting point), rpm'* being above a certain level for I think it was 10seconds, and a few other things. The only factor with a T-stat is that it starts looking at these variables at or above 160degrees. Also, even if you could keep it in open loop chances are better that you're running a little lean rather than rich. Carbon buildup, dirty injectors, and blowby all work to lean out the combustion mixture. Most older cars have to compensate by adding more fuel. If you stay in open loop this correction won't be made.

The only temperature mechanism that directly affects fuel (that I know of) is the IAT sensor. (ok technically the MAF too) I've not read any reliable information that says colder block temperatures mean more fuel after closed loop operation.

Dr. Jay...

You're like the BC'* Regular Myth Buster

I will agree.. I cleaned my K&N on my older car and didn't have time to wipe or let the oil settle and it made a huge mess and screwed up my MAF sensor. But that would be like overdoing anything. that would be like cleaning the engine compartment and block so clean that you strip the bearings seals and all the grease off the pulley and such.. when things are overdone.. to most degree isn't good ( same with boost if it'* engine isn't setup for it KABOOM )

The oil additive I never use any.. I don't really see a need for it. If you get good oil all the time then you'll be fine. I was researchin into sea foam and GM top engine cleaner.. but I think in summer I will just use water mist to steam clean the engine instead.

lol well someone needs to be! And right on about the filter, it seems you just have to be a little more careful to save from causing problems. I don't have personal experience with this though.

thanks for the feedback...

only thing i ever add to my bonne'* oil is Slick 50 oil additive. that stuff works wonders. i have used it for years, with no problems. i figure if one was going to develop from using that stuff, it would have happened before 121,321 miles.

Hey Bill.. can you change Doc'* name from Resident Gearhead to Resident MythBuster?


AS for the T-stat with MPG.. I notice it drops just a tad.. not really noticeable unless it'* by the whole tank and it ain't that much.. right now with the cold winter coming.. I notice a major drop in MPG.. but with cold weather the car runs richer.. ( and proves Dr.Jay'* point that IAT and MAF along with a few others control the MPG more then just a T-stat )

FYI
Bout oil Additive
http://www.bobistheoilguy.com/images/lucas/lucas.htm

Thats Funny - what will someone thing of next?