Royal purple is starting to suck
 

I've been using royal purple for like a year now. I've been using 10w-30. The problem is I heard from some people that royal purple in the oil industry is it kind of sucks. Also Royal purple keeps raising their prices. Before I got it at $5 a quart. Then at $5.50, then at $6.00, and now at $6.50 a quart. That price is just outragious.

It's royal purple synthetic 10w-30. Now I want something cheaper but still synthetic. Also I made a thread about switching from 10w-30 to perhaps a 5w-30 or even a 0w-30. What are the pro and cons of switching to a thinner synthetic oil??? and what I can switch to, 5w-30 or 0w-30?

Also what other synthetic can I substitute it for???

ok, so now I understand that
 

ok, so now I understand that staying with the 30 will do diddly for fuel economy.

The fuel economy oil that I saw was 0w-20 and 5w-20.

0w is best for start ups, because it flows the best at start up. 20 is better than 30 because it is a thinner oil.

The best oil would be 0w-20, but the main question is will my engine like 0w-20? or should I downgrade to 5w-20 and maybe that will work on my engine?

look what I
 

look what I found...

https://www.carwashmag.com/pdf/sept_2005/thicker.cfm

since I'm using 10w-30 and if I switch to 5w-20 I'll save 1% of gas.
I'm getting 28mpg and if I start using this I'll gain another .28mpg. Every little bit helps.

I have been using 0W-20
 

I have been using 0W-20 Mobil One in both the Prius and Del Sol. I also use it in the Del Sol Transmission. I can't quantify FE gains since I have used it since day one. I can say that I haven't had any problems and everything is running just peachy. In the Prius I change every 12-15k miles. I plan to do the same in the Del Sol which has about 4k on the oil right now. The increased oil change interval helps to offset the additional cost of the oil.

what is the recommended oil
 

what is the recommended oil for your car???
it's probably 5w-30 or 5w-20. Mobil actually says that if you use 5w-20 you can safely use 0w-20.

I doubt I can just go from 10w-30 to 0w-20, that is a huge difference.

matter of heat
 

you would just have to keep in mind your start-up and operating temps. Zero weight oil is good for starts in colder areas, but sometimes not so good for hot depending on your engine. The key is to have the oil thin enough to promote good starts, but not too thin to the point it doesn't stay where it needs to(in the bearings and such). On the other side of things, during operating temps you want the oil to be viscous enough to protect the engine, but not so much as to resist the movement of the rotating mass. It's really hard to say what could work in an engine other than the factory grade oil. I would say that if you live in a temperate climate and don't race your engine or anything, 0w20 or 5w20 should be ok. However, if you live in a hot climate, we're talking 100 degree summers, you're probably better off with 5w30.

my manufacturer is saying
 

my manufacturer is saying 10w-30 and 5w-30 is okay. The difference between those is the viscosity on warm up. I think I'll just go with 5w-20, that way the viscosity for warm up is thinner and the viscosity on a warm engine is good too. I'll also do 3000 mile changes, not to give the oil a chance to start to break up.

I live in a warm climate, there is no winter here. It's rare for 100 degree summer here. It stays 85-90 degrees.

you should be fine then
 

You'll be fine with 5w20 then. The cheapest synthetic oil I've seen is valvoline at around 4 bucks a quart. oh and FYI, if you're still looking for RP oil, mustangtuning.com has it listed at 5.48 a quart with free shipping to anywhere in the continental US. That's where I got mine. Just don't tell them you don't have a mustang... }:)

Re: what is the recommended oil
 

5W-30 is recommended for both of my cars.

I didn't recommend that you do anything. I just told you what I do. Similar to tire pressure. I don't recommned filling higher than the sidewall max pressure. But I typically overfill by 30-40%. In both cases, I have had no problems and I don't anticipate future problems.

Re: what is the recommended oil
 

I know that you don't want to be held liable or anything like that. I just take your advice and whoever else is doing things that thinks outside the box. My tire pressure is 55psi on a 44psi sidewall tire. I don't want to go beyond that. Next time I'll just buy a taller tire and do the same 55 psi. I think it would be safe for my car to go with 5w-20, the only difference between 0w and 5w is the warm up. I'm not making drastic changes with going to 5w, the only thing I'm changing is the viscosity on the warmed up engine. Either way it's a win-win situation, I'll pay less for better oil and I'll gain some fuel economy.