Is it okay to mix Honda Oil GN4 (10W-30) with Honda Oil GN4 (10W-40)?
Really need to do an oil change before this weekend's ride and all I have is 1 quart of
10W-30 and my local dealer only has 2 quarts left of 10W-40. So since my 2009 Rancher 420FM requires 3 quarts looks like I may need to mix my one quart of 10W-30 with the two quarts of 10W-40. So I am wondering if this is okay. I ride in New Hampshire and the trails are mostly technical, I do not make it out of 3rd gear very often. So the machine probable runs hard.
Also looking at the 10W-40 it has the letters JS after the 40 (10W-40JS) but the JS is not there on the 10W-30 anyone know what the JS designates?
My owner’s manual and my service manual does not give any insight into whether or not I can mix and what the JS would stand for so I was hoping someone could help me here.
Thank you, Don

 

In a pinch its ok. I top off amsoil 0w-40 synthetic with conventional 10w-30 on a long 100 mile ride years ago without a problem.

Even the amsoil bottle say it can be mixed with conventioal oil right on there lable.

 

See this post for a lot of great basic oil info:

http://forums.atvconnection.com/showthread.php?t=310291

I mix oil all the time! In hot summer weather, my dual-sport motorcycles get ridden for daily commuting. I run Maxima Extra in them, and 10W40 is kind of light, but 15W50 is a little to much, so I do a 50:50 mix....no big deal! I guess that gives me a 12.5W45!

If you read the post I quoted above, you will realize the importance of an oil being API SG! Honda's oils were SG until a couple years ago, but now are SJ. This is suspicious!!! The thing is, SJ has a downgraded anti-wear additive package compared to SG, because of catalytic converters.

What I think Honda has done, is made their oil SJ because then they can then sell the same oil to street bikers with cat converters, and off-roaders. I guess that keeps things simple for the dealers (????). You however do not have a catalytic converter, so there is no reason not to run an SG oil!

Personally, for this reason I will not run Honda's oils. If you have been running GN4, find some Maxima Premium insted. It is comparable in price, and Maxima has the best additive package in the industry. Better yet some Maxima Extra, but it is about twice the price.

 

I recently took recons advice and switched oils from belray to maxima 530 mx and the difference was huge. engine sounded healthier, clutch felt a lot smoother and got some hp gains. Gn4 is alot cheaper than maxima, buts lets face it,we all want our machines to run at there top form as long as possible. rmatv.com has some good deal on maxima. 11.99 for my 530mx. If you make the switch you will not regret it.

 

Hey recon, how much would the oils you mention cost? Been looking for good quality synthetic. Can you buy it in bulk? I've seen on here that you can run 0w 40 synthetic in the rubicon as long as you don't reside in the desert SW region. The manuals spec 10w 40 but that is a little thick at -40 F up here in South Dakota. I would think as long as its a 40 and wet clutch comp then it should be OK. Whats your take on this? Or should I custom mix 2.5w 40 by using some 10w in the 0w? Our average temp up here in the summer is about 80 F. I only use it to ride around town, pull an occasional drag, and herbicide application. I only put 20-30 hours on it in the Summertime and if its over 80 F, I rarley use it. I put alot more hours on it in the winter, mostly temps under 20 F. Thanks in advance for your input.

 

I would however switch back from 5W30 to a heavier weight for summer, especially if you are where it is really hot (see your owner's manual)! If you find you like a highly friction modified oil, then you might want to try Redline or Maxiam Ultra.

 

Don't stray to far from what your owner's manual recommends, for the current outside temperature. Most wear occurs at a cold startup, so you don't want your oil to thick in cold weather. On the other hand, when it is very hot, you don't want it super thin either. I don't think there is an ideal year round oil for most climates.

Modern water cooled engines have tighter tolerances than the old school air cooled ones. So, you don't need such thick oils to bridge the gaps in bearings and such. Honda in particular, is specing lighter oils, even for hot weather. It seems weird to me, but my Rancher 420 specs 0W30 and 5W30 as year round oils. It also specs 10W30 and 10W40 for warmer weather, but I think one would be nuts to run the very light oils in the hot southwest!

 

thanks again recon. will do

 

Thanks everyone and thank you reconranger for the additional reading. I have done my oil change with 1qrt of 10W-30 and 2qrts of 10W-40 so I am basically running 10W-36.67.

One last question for reconranger, took a look at Maxima oils and I am most definitavely going to swtich over. Just curious what the difference was between their ATV Premium 4T oil and their Maxum4 Premium. I am looking at 10W-40 weights. Both are wet clutch safe, both are made for ATVs both are the same price per 5 gallons jugs, the only difference I see is that Maxum4 Premium says turbo safe. Just curious what is best of these two for my Rancher 420FM.

 

I mix weights on almost every one of my vehicles. I try to match companies and types but the weight isn't important. Although I have been known to use 8 various half quarts of oil to change my cars oil.....Although I did only pay $25 dollars for it.