yes transmissions have changed quite a bit. toyota,honda,chrysler,and a few others use a special low friction formula. the yno longer use the dexron/mercon anymore. just chevy and ford still use it. they actually started the switch in the mid to late 90's( toyota and honda)
as far as information on the oil it is pretty simple, i base it on the thousands of cars i work on in a year. it does seem that the engines that use synt are in a bit of better shape than those with dino oil.Of course that is just based on 3k or 6 k oil changes whichever the case may be ,and general appearance of the head (looking in the oil filler hole) dino oil seems to leave varnish whereas syth does not. also on the chrysler engines with the huge filler holes(like the jeep 3.7) I have seen less condensation with sythetic than reg oil.
as for the rear diffs many newer four wheel drives use a special fluid if it has limited slip, gm and chrysler has been using additives for those for years, until recently. now they use sythetic gear oil in most cases, while some ***** companies still use the special LSD oil. there are alot of things that play in the role of oil changes.Such as temp,driving habits,how often you drive and so on. as a chemist you should know that anything natural breaks down faster than what is created by men. such is the case between the oils,while dino oil degrades,causing varnish,loss of viscosity and so on over time sythetic does not lose its quality as fast. why do you think manufacturers recommend 3k or 3 months whichever comes first on dino oil?
his question was should he use sythetic like jippy lube told him his jeep takes or just regular. i told him to use what the jeep reccomends(which i think is mopar +4 tranny fluid) and toldd him to check the tag on the diff to be sure it uses sythetic. While it won't hurt to use a synthetic in a non synth rear it will harm it if it needs it and you don't use it(like in LSD rears)
Beleave it or not i have looked at quite a few tests,seen pleanty of evidence,and kept up with compairing regular customer cars with one another to see what was working better. sure i took info from what i was told, but i also looked at things with my own eyes and done my own tests. That is how i got my info. by listening to what the experts say,taking mental notes and doing my own research,and testing.The oil i use is the weight the manufacturer reccomends I use regular oil in my jeep because this late in the game after the years of abuse from previouse owners syth is a waste of money. on the other hand since we baught my wifes car new and we treat it with respect I am willing to put syth in it to help it last longer.
as for the break in time on a car you know that is when the car will burn oil and wear the componites a bit, which is how it finally gets sealed properly. as mentioned before dino oil breaks down quicker,the dirtier it gets the worse it gets. sythetic keeps it's integrity longer, thus the metal shavings does not affect it from the break in period like it will regular oil.
several auto manufaturers actually tell you to use sythetic in their cars,and some tell the brand . most german cars tell you to use castrol, certain mercedes tell you to use mobile one as well as chevrolet in their corvettes and chryslers with their hemi's. we have had dealerships tell us if we didn't use what they reccomend that they will void the warrenty. what it really boils down to is use what the manufaturer tells you to use.
Yes filter changes are important as well as you said, i am sure people can argue on brands of filters as well. I am using what I always used,and until fram if fram ever does something wrong continuously i will keep using them.
Fred don't worry about coming down on me hard,I have been here long enough to know you mean the best,and frankly I enjoy having you question my info. it makes me go back to double check and either prove my case,tell you where i am coming from or to realize I made a mistake.This is how we all learn from one anothers knowledge. <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" />
