Hey folks, I’m putting together a new ATV and trying to decide on the oil mix. I’ve seen recommendations for both a 40:1 and a 50:1 ratio. The 40:1 mix seems to give better lubrication, but the 50:1 would let me stretch the tank a bit longer between fills. I’m planning to run it mostly on moderate trails with occasional heavy loads. Anyone here run either ratio on a similar setup? How does it affect engine heat, wear, and fuel consumption? Would love to hear real‑world experiences before I lock in a ratio.
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what has more oil 40 to 1 or 50 to 1
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Mike HendersonJun 17, 2026, 8:07 PM
I ran a 40:1 mix on my 700‑cc ATV for a couple of years. The engine stayed cool even on steep climbs, and I noticed less oil consumption at high RPMs. The downside was hitting the fuel cap more often – about every 12‑14 hours of run time. If you’re doing a lot of heavy pulling, the extra lubrication can be worth the extra stops.
Kevin BrooksJun 17, 2026, 8:07 PM
I switched to 50:1 after reading the manufacturer’s spec sheet, which actually calls for that ratio on newer four‑stroke engines. My fuel mileage improved by roughly 5%, and I haven’t had any oil‑related issues yet. The trade‑off is a slightly higher operating temperature under hard load, so keep an eye on the temperature gauge and consider a larger oil cooler if you push it hard.
Ryan EdwardsJun 17, 2026, 8:07 PM
From my experience, the difference is marginal unless you’re in extreme conditions. I ran 45:1 as a compromise and never saw any major wear signs. The key is using high‑quality synthetic oil and changing it regularly. Also, remember that a richer mix can mask early wear, so stick to the service interval regardless of the ratio.
Derek ColeJun 17, 2026, 8:07 PM
Safety note: the wrong mix can cause carbon buildup and spark plug fouling. I once used a 30:1 mix on a newer model and ended up with a fouled plug after just a few weeks. If you decide on 40:1, make sure you’re not exceeding the oil’s maximum viscosity rating for your climate – cold mornings can make the oil too thick, affecting start‑up.
Sarah CollinsJun 17, 2026, 8:07 PM
I’m a bit skeptical about the fuel‑saving claim of 50:1. In my 950‑cc rig, I tried both ratios side by side on identical routes. The 50:1 run actually ran hotter and I had to back‑off throttle to keep temps down. The 40:1 felt smoother and the engine sounded quieter. If you prioritize engine longevity over a few miles of range, go richer.