Recently changed my engine oil on my Suburban, a '92 @400,000+ miles. Since I have found Mobil One increasingly difficult to find I used AmsOil. This change was 7,000 miles ago now. I put in 0W-30. I had put this engine on Mobil One at 5,000 miles so its been on synthetic for virtually all of its life.

I track mileage in a spreadsheet. I have seen >8% increase in fuel mileage since putting in AmsOil. Didn't even think it'd make a difference since I went from synthetic to synthetic. I've been told that Mobil has moved their formula down from pure synthetic. I'll do some homework on this.

Haven't changed my FEH yet, as its not due. More to follow though when I do.

 

the mobil 1 extended performance is just like the old version=more supersyn. so, really you got 400,000 miles on your burban?

 

409,573 to be more precise on the OEM engine. Yeah, I used this Amsoil stuff since I can't get what I want, when I want from Mobil One. The Amsoil is available and appears to be good. Like I said, more to follow, but I just couldn't believe it as the numbers accumulated on mileage.

 

I just used the maintenance minder on my escalade hybrid myself and it also lasted 10K miles before it showed 13% oil life left. just sent out a blackstone sample and will see the result. my 03 pilot has 178K miles already and have used only mobil 1 synthetic since break-in oil.

any pics of this 'burban? thanks!

 

So what other factors could contribute to this?

I just ( temporarily ) boosted my MPG by 20% by changing my 12v underhood battery.

It was not the brand name that made the difference.
It was the fact my computer settings all got reset to default.

 

I've been using the Amsoil XL oil over the last 2 oil changes (20,000 miles). As best I can tell, that's what they call their multi-blend (partial synthetic).

I will move over to their full synthetic for my next change. I'll report back if I see any appreciable FE change (would love to see a +8% like Bill).

 

I've used Amsoil since just before Mobil 1 came out. Love it. Their filters are very good too, some say WIX re-labeled, some say WIX made to Amsoil spec. I've done it their suggested method: change your filter 2x year or every 5k or so, add fresh oil to repl what gets lost with your filter change.

Now with my FEH and its "element" filter, I've changed both when the dashboard message tells me to (so far), and I'm curious how much oil I'd lose if I didn't drain the crankcase before I removed the oil filter housing. Last I checked, Amsoil wasn't selling a filter for the FEH, but OEM or WIX was all that was available.


62k mi.

 

I'll work on some pics of the Suburban... its a 1992 bought new... and it looks 18 years old, but not in bad shape, all in all.

All other probable inputs to the equation were held constant...

The Amsoil people will tell you that Mobil One has dropped down to a grade 3 formulation. I have not verified that yet.

No idea whether this'll show up in my FEH or not.

Like I said more to follow but it may be awhile.

 

A '92 Suburban with 400,000+ miles will most likely get less than 15mpg on average. At a 8% increase in MPG we're only talking about a 1.2mpg increase. A weather change during this period, a change in route, longer trips and smaller loads could all account for 1.2mph. Bill could have also picked-up some driving changes since he bought the FEH.

An 8% improvement in my '09 FEH mpg would increase my mileage by 4.8mpg and if that were possible, I'd do it in a minute.

GaryG

 

Well Gary, we are convinced you track your MPG as close, if not more closely than anybody. I agree that 'most' folks would not be able to notice an 8% change. I feel you could.

Your best best now is to flush what oil you have in there now ( change oil to Amsoil, drive 100 miles, drain, and refill with clean Amsoil ) and then drive a few tanks and a few thousand miles to average out all the weather and cargo variations and report back.

This could be your greatest discovery since the Scan Gauge.

( A Hem.... well..... Bill's discovery, but your validation. )

This is called good science. Hat's off if you do it.

One data point is a fluke.
Two data points in agreement is a coincidence.
Three or more, and it starts to become reliable information.
Maybe others will pick up the challenge?

My problem is, I do not have a regular driving routine, so 8% would be hard to find in all the "noise". ( I tow, I go on long trips, followed by days of short trips, I buy gas in 42 different states, 12 different states on a regular basis....) So I'm not chicken to try it, but I see big variences in gas quality from state to state.