Engine Oil weight question...can u go thinner?

[AnthonyF]

I've been wondering this for awhile, some might too. I would like an answer from some1 who KNOWS there shit. Not a frigin poser who is a know-it-nothing.

my car requires 5w-30. I changed the pistons to forged and is a lower compression 8.8:1. Could I run a 5w-10/20 or even a 0w-5/10?

my car is driven about 100 miles in a single day on hwy in shitty ass traffic and used on the strip. So i wanting a good smooth motion for my motor. any help?? Appreciate it!

[Sol-Badguy]

I don't know, but I saw you today on Buford Highway.

Sounds mean.

All my turbo cars for 5W-30, though.

[optik678]

From what I've seen of information on the internet, the more power you make, the more protection you are going to need for your engine components which means THICKER oil, not thinner. 15w40 or 15w50 is what a bunch of the higher horsepower turbo cars run that I've seen (I run it too).

[AnthonyF]

I don't know, but I saw you today on Buford Highway.

Sounds mean.

All my turbo cars for 5W-30, though.

thanks man! what car were you in??


I was tearing up the streets of La Buford Hwy. lol

[AnthonyF]

From what I've seen of information on the internet, the more power you make, the more protection you are going to need for your engine components which means THICKER oil, not thinner. 15w40 or 15w50 is what a bunch of the higher horsepower turbo cars run that I've seen (I run it too).

appreciate it man. Ive been just putting 5w30 in it. that should be think enough.......... ......i'll will try new things.

[TIGERJC]

I have always used mobile1 10w30, but I would go thicker since it is the summer in your case

[Vteckidd]

i woulndt go thinner.

i would actually prob go a little thicker

[AnthonyF]

well it is 4-0 with the thicker. appreciate it. Im not boosted right now but when i get back to it I will prob shoot to a 10-30 then.

[Vteckidd]

well especially in stop an go traffic, you want an oil that wont break down fast, and can withstand alot of heat.

[AnthonyF]

That is true. thanks, i tend to over look a few things.

[blackshine007]

Thinner oil has has better viscosity values, but deminishes the cooling, which in simpler terms breaks the oil down quicker if you just so happen to be born with a heavy right foot like all the rest of us in these forums were. More load = more heat. Going Full synthetic can only do but so much. Yeah, it's true that full synthetic has far better viscosity values than the good ol petroleum based oils do. But you would want to make it slightly thicker to help transfer some of the heat. I thought Most Fords run 5w20 nowadays, so a better upgrade for the summer would be 10w30, or even 10w40 if you're boosted, or boosting. Some engines just aren't designed to run significantly thicker oils. It puts too much wear and tear on the oil pumps because of smaller passages the oil has to go through, the pump has to work that much harder to do the same job. And since you want the best in your engine, it has been proven in most test that royal purple is the best. I think Amsoil or mobil 1 was next in line. I would personally stick with royal purple. It's proven to do the job right.

Damn, I sound like a commercial, lol

[TIGERJC]

I wouldnt go royal purple unless I had a rx7, b/c that stuff is too damn exspensive. I use mobil 1 and chang my oil whenever it stop looking the way it looked when I first poured it out of the bottle (about every month)

[Turbodude06]

^^^ damn and I thought I was bad about changing my oil every 2000 miles..... I'm no expert but I've always done thicker in the summer and thinner in the winter due to the temp changes, but that is what I was always told.....

[blackshine007]

^^^ damn and I thought I was bad about changing my oil every 2000 miles..... I'm no expert but I've always done thicker in the summer and thinner in the winter due to the temp changes, but that is what I was always told.....

I run Mobil 1 full synthetic because I don't feel like driving way the hell to the other side of town to buy 5 qts of RP. And while I'm at it, I don't even use the stock oil filter any more. My filter is the same EXACT filter that the K series guys use for their hondas. I said screw that years ago and now I run a Corvette ZR1 oil filter. I also change my oil every 5k miles because most of the time I'm driving the car easy. Gotta love a V6 that averages 28 mpg!!!

[Turbodude06]

^^^ hell yea My SI only gets 27 mpg....

[AnthonyF]

^^^ hell yea My SI only gets 27 mpg....

My Supercharged mustang gets 24..with me on it a lot of the time.


appreciate the help guys, reps given.

[AnthonyF]

i do not/will not use royal purple...i dunno. Just something about it. I get the creeps from it. lol. I usually dont use the new stuff. I like to keep to what has been working great for many years...like I run AutoMeters cuz 70yrs in the business vs faze which has been a few. And..the bottle isn't as nice as Mobil1's. lol.

[blackshine007]

My Supercharged mustang gets 24..with me on it a lot of the time.


appreciate the help guys, reps given.

Most force induced cars tend to get better gas mileage than their naturally aspirated versions due to less pumping loss on the engine itself. In other words, it's not working as hard to do the same job. But That also come from good tuning too. I'm almost positive that someone will come on here and say how they get 2 mpg from their turbo car. But once again, it's in the tuning. You can run lean when out of boost. About 15:1 is about as close to the envelope as I would take it. Anything higher, and you're starting to fail emissions due to higher NOX levels, but aside from that, you could go no higher than 16:1 without any adverse effects.

And no problem, I live, breathe, and sleep automotive. Besides, I like showing off my ASE certified talents on occasion