Forgot and left 30wt oil in tractor over winter

Jan 9, 2008
I keep my 425 in an unheated separate garage and forgot to change out my summer straight 30wt oil. Now it's in the single digits and I'd like to change the oil so I can use the tractor to plow with. Should I wait for a warmer day or just go ahead and start it.
What are day time high temps and temp in garage mid day it turns and fires up run it.
amazon has an oil pan heater, $22.(ish) probably worth it to keep fluid flowing.
It will fire up and run fine down to about freezing. So it's only really necessary to change it if you are starting the tractor a lot below about 25F. And it's going to flow about the same at those temps as the multi-weight at least down to freezing - nothing to be gained. Now if you ARE starting it a lot below 30F or 25F, then change it. You can just drain it out cold and refill with enough 10w-30 and not worry about heating it up and doing it 100%, that will be enough.

Here in western wa where it rarely gets below freezing, we do not change the oil for winter and do not worry at all starting it in the few days in the 20s when/if it does snow duty.
If your going to need it in the morning with the temps in most of WV in the lower teens I would just drain it cold and refill. If you can wait until next Wed. we might get into the mid 40'S and you can warm it up before changing.
Unless you have a lot of time, you will have to heat the block to drain because that 30wt will take all day long. I would still take the time and let it all drain out to refill with a 5w-30. I don't think starting the engine is a good idea with current temperatures and a straight 30 is in the crankcase.

I’d let it drain all late afternoon/ night or early morning before you start your day. Less “waiting” IMO as you can leave it and walk away. Who knows how long it’d really take.
An sae 30 has a kv 40 of 105 while 10w-40 is around 108. I'm sure it will still turn over just fine but I'd let it idle slowly for a half minute then slowly use it. Once you're done you can drain it after it cools a bit.
I had a customer drop off a snowblower for service, it had straight 30 weight in it. It sat out all night long with this morning's temp being -2 F. I went to move it before leaving for work, and when I went to pull the starter rope it wouldn't turn over the oil was so thick. I actually snapped the rope right in two, and dislocated my shoulder. Imagine if this engine was larger than 5hp. :oops:

.....just kidding. It started easily on the first pull. The OP's tractor should start fine.