i realized i got 10w-40 instead of 10w-30. Is 10w40 alright to use or should i go back to the parts store and get the 30

 

you're fine. 10w-40 means, 10 is the weight at start up and 40 is the weight at normal engine temp. A lot of people here run 15w-50. You'll be just fine, you what a heavier oil in the summer months and a lighter one in the winter.

 

Zack you are here in LA man its hot! You should run the 40 if not higher. I have always ran 15w-50 Mobil 1 sythetic because it gets hot as hell here and there is no winter, LOL. Never had a problem starting her up.

 

You shouldn't have a problem with 10w40, in fact I believe it's going to give you better engine protection than most of the 10w30s out there, which are too thin, most of them are on the low end of a 30wt. I do believe the LT1 will show better wear numbers with an oil on the thicker side of a 30wt, to a low 40wt oil. So if you look at the specs on the oil, it should be in a range of about 12cst at 100c to 14cst at 100c.

Which brand of 10w40 is it?

 

I used Valvoline Max Life 10w-40

 

DON'T DO IT!

It is a massacre. If you don't believe me, just take and taste the difference between 10W30 and 10W40.

Just kidding.

Pour it in and ride!

 

I have used the Valvoline Max life since I hit 100k.
10w 40 is all I use.

 

I'm not a big fan of Maxlife, but you should be fine for this one oil change. I found that Maxlife holds it's viscosity very well, and holds it's TBN well too (it's acid neutralizing capability) however I saw more bearing wear (shown as lead on oil analysis) compared to Schaeffer Supreme. Maxlife used to be much better until they dropped the moly from their formula. Moly is one of the anti wear additives that many oils have recently added, but Valvoline is moving backwards and took it out of their formula, but didn't really add anything else that would replace it (such as boron or antimony for example) Maxlife also reduced their zinc, phosphorus and calcium levels at the same time too. Not good.

If you like the high mileage oils, go with GTX HM 10w30 or Pennzoil HM 10w30 on the next oil change. Both of them are very thick 30wt oils.

 

well, the max life caught my eye since my car just turned over 87k miles and I figured thats considered "high-milage". This was my 2nd change on my car, and honestly, I dont even remember what I used the first time :

 

MAXLIFE 10w-30 since 70k, 82k now and just had the intake off yesterday, probably just as clean as a new engine in there, then again its had mobil 1 since 39k when I bought it....