Can I use Amsoil 5W30 in my 1994 Honda Accord EX?

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Jun 22, 2003
Grand Forks, ND
I want to try Amsoil's 5W30 but I'm concerned because it's not API certified. What is the reason for this?

Can you really go 25,000 miles between changes? Are there any UOA's on Amsoil after 25K and what did they look like?

How does Amsoil 's 5W30 compare to Mobil 1 SuperSyn?

Will Amsoil 5W30 harm my engine?

Is there any store I can buy Amsoil at in my area? Or how could I go about ordering it?

[ July 01, 2003, 05:19 PM: Message edited by: MinnesotaNole ]
Since your car's been off warrantee for, i'm guessing, 5-6 years, go right ahead.

Some of the smaller oil blenders, like Amsoil, don't want to spend the significant bucks it cost to get the oil API certified. This is an issue with a new car under warrantee, since not using certified oil could, in theory, give the car mfgr a reason to deny a claim.

If you believe Amsoil's claims that they meet the certification criteria, but just haven't submitted it for financial reasons, go right ahead and use it.

FWIW, why don't you just use Mobil1 instead. It's $5 bucks a quart (or less on sale, sometimes signficantly) and available anywhere. I've never heard anything conclusively showing any benefit to Amsoil over M1. And M1 IS API certified.
Are you willing to bet your engine on that claim? Contamination and additive depletion will probably necessitate changing the oil way before 25K miles.

Mind you, I'm not saying it's bad oil. I just don't think that it's worth jumping through hoops to use it, when what I consider an equivalent product is so easily available (and actually superior by way of having the API cert).

I can't say I really believe that extended drain claim. FWIW, Mobil 1 did claim that when if first came out. After a raft of complaints about warrantee issues, they gave it up and went back to saying to use the mfgr recommended interval.
To the peanut gallery: Has anyone seen a UOA of Amsoil (or any other passenger car oil) at 25,000 miles?
Do a search, there is a ton of info. waiting to be read.

[ July 01, 2003, 05:35 PM: Message edited by: buster ]

Originally posted by MinnesotaNole:

I wanted to try Amsoil because of their 25,000 mile interval claim.

Can Mobil 1 go 25,000 miles?

Mobil 1 doesn't recommend it. The reason Amsoil is not API certified is not solely just the cost of doing so. Their extended service oils use more ZDDP than API SL allows, so they couldn't be "SL" certified even if they wanted to. This is neither "good" nor "bad" just a different formulation. It MAY reduce wear on the engine but it also MAY kill your catalytic converters more quickly. Lots of debate on that subject.

The net net is that both Mobil 1 or Amsoil will do the job well. But if you want a 25000 mile oil change Amsoil is the way to go. But if you are going with the extended interval, you might want to analyze the oil every 5k to see whether it's holding up...

Personally, I would never use a 25000 mile change interval. If my car were so cheap I didn't care (like my old Honda Civic) I'd save my money and just use regular old cheap dino juice. And if my car were so nice that I wanted to use syn oil (like my Panoz or Lexus) then I'd use the syn oil and change it every 5k to 10k miles.

[ July 01, 2003, 05:38 PM: Message edited by: MRC01 ]
As stated in your case the warranty is a non-issue. The oil easily passes the performance part of SL, but indeed with a P over 1000 ppm it exceeds that criteria. I actually think the P over 1000 ppm "poisoning" catalytic converters is BS. Oils have been over 1K P for YEARS AND YEARS and cats havn't been killed due to this.

Yes Amsoil ASL (5W-30) can go 25,000 miles. I went 20K and the oil still had some life in it.

That said - I don't recommend it right away - this is something that you "ease" into. Something like - make sure your engine is REALLY clean (oil analysis with full Auto-Rx process) then go 7500 miles (change oil), do another analysis, 15K, etc....some cars it's easier than others.

Amsoil 5W-30 will not harm your engine. Buy from one of the sponsors here. In the west (N.D.) - me. Shoot me an email - I have a BobIstheOilGuy discount. In the east either ted or mike.

[ July 01, 2003, 07:09 PM: Message edited by: Pablo ]

Originally posted by MikeW:

Some of the smaller oil blenders, like Amsoil, don't want to spend the significant bucks it cost to get the oil API certified.

In most cases, the additive package suppliers, Lubrizol, Chevron-Oronite, Infinium, Ethyl Corp., get the API approvals and the oil blenders buy a pre-approved additive package. Amsoil goes it almost alone with their high phosphorus, low volatility, and greatly extended drain interval.


Based on my own oil analysis testing, I'd recommend a 15,000 mile/1 year drain interval with the Amsoil 5w-30/10w-30, including a filter change and topoff halfway through. Under ideal conditions you can run the oil even longer, however it will thicken a fair amount due to oxidation and the TBN will get pretty low after 20k-25k miles. So in order to get better long term results, I think it's better to be a bit conservative.

The three major factors in determining maximum drain intervals are:

1) Severity of driving conditions
2) The mechanical condition of the engine - including any aftermarket mods
3) Fuel quality and the use of fuel additives - the latter is generally beneficial but can be overdone.

Honda tends to make pretty clean running engines and I've had good results with Amsoil in the Honda/Acura motors ....

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