Silver2001GT

Hello everyone

new to the forums here and I have a question about oil.

My 2001 GT is supposed to take 5w20 (as they all are) but my last change, I went with 10w30, seems to run fine, and now I am about to change it again keeping it at 10w30 and running Royal Purple.

Now I'm kinda new to the whole modding scene but I'm liking it so far and trying to learn as much as I can.... what is the real difference between these oil grades? and will running 10w30 and NOT 5w20 be ok for my engine?

No engine work has been done to the car, only mods are a CAI, Flowmaster mufflers, SCT tune, and a bunch of exterior stuff.

Thanks in advance for all the great advice I'm sure you guys have to offer!

Mustang3GT07

Just run what your car calls for!

cliffyk

I run 10W-30 year-round in my '03 GT (105k miles) here in Florida, I have ever since I got it with 30k on the clock.

It's 20W-50 in my wife's '03 Toyota Highlander with 145k miles on it.

Here's an interesting piece about 5W-20...

98redstang

I run 10w-30 works for me. Running at the track i burned through that 5w20. I had to add like a pint every week and a half.

nascrchi

wow! That was a very imformational article.

Pretty much there is a take one or the other effect. If I opt for a decrease in viscosity, I get better MPG(1%lol)because the engine doesn't have alot of motion resistance, BUT reduces engine life.

If I opt for an increase in viscosity the engine has more motion resistance which decreases MPG, BUT most importantly increases the life of my engine.

I can't believe manufactures falsify buyers to buy again lol

thanks for that cliff

Silver2001GT

thats some good info in that article, thanks for shedding some light on the subject cliffyk

PA isn't the warmest state but I'm pretty sure it won't be -30 degrees C here anytime soon haha or whatever temp the article said the oil will have trouble with

Eagle2000GT

5w-30 means that the oil acts like 5 weight oil on start up and 30 weight oil at operating tempatures. In the old days (before multi-grade oil) I ran 30 weight oil in the summer and 10 weight oil in the winter. On very cold days, my car would hardly crank over during the winter if I left 30 weight oil in it. Add that to a weak battery and you can't even crank the motor over. During the coldest parts of winter it may have been best to run 5 weight oil. (I have seen -20 and -25 tempatures here in Indiana.) In Arizonia I ran 30 weight all year long.

I recommend 5w-30 as an alternative to 10w-30. Pennsylvania is not as warm as Florida and it would provide better cold start portection than 10w-30.

P.S. I thought people were running 5w-20 because the oil return passages in our motors are somewhat restrictive and it allowed the oil to flow back to the pan better; thus, under high rpm operations, you were less likely to pump the oil pan dry.

CliffyK, if I ran 20w-50 in anything up here I'd never get the car started in the winter. 10w-40 caused the lifters in my truck to rattle bad until it warmed up. I didn't even wait for the next oil change before going back to 5w-30.

devongarver

damn...looks like im movin up to 5w-30 next change lol.

nascrchi

lol yup

Frostbitten

5w30 for me