If you've read my first post, which I'd be surprised if you could indeed read. My biggest pet peeve is people who try to spend more time on gas mileage than horses... That was simply my rebuttal to your sorry statement about how LS1's will be better than anything I could create and all that but whatever helps you sleep at night.
Just to keep on topic... keep a light foot. That's %75 of most people problems. I was getting about 9mpg on my dodge ram 5.9 until i took it easy and now i see about 13.5. synthetics help out a bit but it is very minimal. I saw an extra .5 while using Mobil 1.

 

Yea, I would agree with that. I am curious how much wear on the engine costs on mpg... If I ran Mobil one right after break in for 100K miles and in the exact same setup in another car I ran walmart Dino juice for 100K then switched to mobil 1, what would the mpg be with mobil 1 in both later in their life.

Mobil 1 claims nearly no wear at 200K miles (I believe I saw that in one of their commercials.) Would bearing wear increase friction noticeably? I suppose the smaller cam lobes from little protection might help mpg a bit .


Tune a carb for a 14.7:1 at wot, and tune for mpg on bottom, good, but at acceleration (Even mild) you will dip into the WOT tune and waste a bit of gas. And if the chip is tuned right, The FI will always pick the best mpg for throttle, and only at WOT go for max hp ("14.7 theoretically")

Ahh, I see, so great if he lives in germany near the autoban, or the AUTOBAD according to the VW radio commercials.

Good info in this post.

 

My '94-'97 T56 with a 3.42 rear in my L98 IROC cruises happily along at 60mph in 6th on flat ground if there is no acceleration needed. If so, 5th works great at that speed. 6th at 65-70mph is okay with light traffic and minor acceleration, 75+ seems fine throughout without requiring enough gas to lug the engine (unless going up a mountain pass or something obvious like that).

 

I wouldn't use synthetic anything in a engine with near 200k miles. Synthetic has those "conditioners and cleaners" which will clean away that sludge buildup thats actually keeping some old motors from leaking. I would switch to regular. Unless.... the motor was using fully synthetic from the start and reached 200k then I would keep using it. One thing I have noticed to work on an import of mine was "restore" its like liquid Zinc , I do not know much about it but supposively it soaks into imperfections and restores compression and all that jazz... I am not sure about all of that but in my eclipse it did get 1mpg better and it also quieted my "lifter tick" I was having. but for V8's it can get a lil pricey but I havent used it on any my domestics as of yet. However, even after my oil change the lifter tick didnt come back. Just something to think about.

 

I convert all my cars over to synth after I buy them, that means as early as 500 miles on my WS6 (the point where I drained the factory fill), a few thousand on my wife’s car to 70-80K on 2 3rd gens and 150K on the truck.

Synth causing leaks and oil burning is a myth that hasn’t been true since the late 70’s, and as far as additive levels causing them, quaker state and pensoil dino juice have the most of the traditional oils but all the extended interval and high mile oils have more of those additives then your normal mobil 1 or RP…

 

I once had an old carbed 89 corolla, had like 180k I used fully synthetic and it started to leak like a **** after a couple thousand. Could be coincidence... but it does make sense in my opinion why it would leak that way. I do perfer syn though over anything else..