AMSOIL at the drain interval it was actually designed for.
100% synthetic motor oils for Central Washington's diesel trucks, V-Twin and dirt bikes, marine engines, and European performance cars — priced through AMSOIL's Preferred Customer program, picked and supported by a local dealer.
Free to ask. No obligation to order.
- Line
- Signature Series 0W-40
- Drain interval
- 25,000 mi / 1 year
- Application
- Gasoline & diesel
- Spec coverage
- API SP · SN+ · CK-4
The engines the mass-market shelves under-spec.
AMSOIL isn't competing with Mobil 1 at the checkout aisle. It sits at the enthusiast segment where drain interval, spec coverage, and additive chemistry actually matter — and where a wrong bottle voids a warranty or costs a season.
Diesel & Tow
Heavy-duty pickups and work trucks seeing long hauls, heavy loads, and stop-and-go driving where drain intervals fall apart.
V-Twin & Dirt
Harley, Indian, metric cruiser, motocross and enduro — high-RPM air-cooled and shared-sump engines that punish lesser oils.
Marine
Inboards, outboards, sterndrives, and PWCs exposed to salt, moisture, and seasonal storage where corrosion resistance matters.
European
BMW, Mercedes, Audi, VW, Porsche — extended drain intervals and the LL-, MB-, VW-spec approvals the bottle actually requires.
Three lines. Pick by the interval you actually want.
AMSOIL's synthetic motor oils split roughly into three tiers. The right one is rarely the most expensive — it's the one that matches how you actually drive.
Signature Series
Top-tier 100% synthetic.
AMSOIL's flagship. Engineered for the longest drain intervals in the AMSOIL catalog — built for drivers who rack up the miles.
Extended-Life
Step up from OE.
A outsized jump over factory fill — for the driver who wants to double the OEM interval without reaching for the Signature price.
OE Series
OE-spec, AMSOIL chemistry.
Stock drain intervals delivered with AMSOIL's synthetic base and additive package. The right call when the warranty is still on the line.
The pricing is the reason you go through a dealer.
AMSOIL's Preferred Customer program is what's actually on offer — not a discount we're adding, not a rebate we're mailing. The dealer referral tag applies it at checkout on amsoil.com.
Member pricing, applied at checkout
Three emails. No new accounts unless you want one.
The dealership side is a referral tag on amsoil.com — that's it. You keep AMSOIL's checkout, AMSOIL's shipping, AMSOIL's warranty.
Tell me the rig and the oil
Email me the year/make/model, the engine, and what you're running today. I'll spec the line, the viscosity, and the drain interval.
I route the order through amsoil.com
You place the order on amsoil.com with my dealer referral tag — the Preferred Customer pricing is applied at checkout, no separate login.
It ships to your door
Free shipping over $100. Direct from AMSOIL's distribution. Free returns if it's the wrong spec — we'll respec before you place the next order.
What usually comes up before the first order.
If your question isn't here, send it over — I read every one.
One email is all it takes to get the right line and the right grade.
Send the year, make, model, engine, and what you're running today. Back with a recommended AMSOIL product and the drain interval it actually delivers — no follow-up pressure, no upsell.
Performance Synthetics — an authorized independent AMSOIL Dealer based in Moses Lake, Washington. Orders are routed through amsoil.com under the dealer's referral tag.