I have about 11,000 miles on my new LT1 engine in my 1994 Z28. What gas do you all recommend for me to run through here? I'm running 89 octane currently, and it seems fine, but with this new engine I want to run the best through it.

Also, on the same note, what type of oil do you all feel is best for this car?

Thanks,

 

The owners manual for you car recommends premium. It will run on 89 octane, but will be down on power and and economy, as the PCM will retard spark timing to avoid engine damage.

 

i run 93 octane in mine and it gets 4-5 MPG better than it does with 89. You can also feel the difference.

 

around where I live, the price difference between premium and mid grade is 10 cents per gallon. At an avg of 18 mpg, and 12k miles per year, that comes down to about $1.28 per week

why does this topic keep coming up especially from people who on the next breath ask about performance yet are worried over $1.28 per week?

To the OP- what's the "best oil"? Well, each supplier will argue that it's theirs which is "best"

if you mean what's adequate and works just fine? What ever 5 w 30 oil/filter special is being offered at Autozone or Adv auto the week that you need it.

If you do mostly stop and go driving then change it frequently like every 2k-3k miles

If you do mixed driving then every 5k is just fine

It's about hours on the engine and the whole 3k or 5k or even 7500 miles between changes is just using averages. You must do it based upon the use of your vehicle.

 

Great! Thanks for the info. I will be using the 93 from this point forward, definately! And I'm running Mobile 5w30 in it now, just wondered if synthetic is that much better for the additional cost. I'm not concerned with spending the extra money, I just want it to last.

 

use synthetic oil. i use moble 1. 5w30 or 10w30 if oil pressure is low. octane makes gas harder to ignite to prevent pre ignition. my stock lt1 ran better with 89 and had no pre ignitin knock. if you hear the knock or lifter chatter then its a really good idea to use ethel.

 

resistance to detonation


now here's a curiosity, your original was a 93 correct? My 3rd gen when it first fires up or goes into closed loop (whatever) wants to hear knock. The computer will try advancing the timing until it gets a knock. If it doesn't get a knock then it throws a code 43

I put in 87 octane and the 43 went away. I wonder if the 93's work the same?

my imports all adapt to higher octane on their own and will rattle under load with 87.

my 07 stang needs a tune for higher octane (silly Ford thing on the 2005-2010)

the new stangs adapt and you even see different HP ratings on the web site based upon octane

the 95 LT1 is tuned for premium

 

The factory recommendation is for 91 unleaded according to the service manual for my '96. The only station that regularly carries 91 in my area is Sunoco.

 

i use 93 oct. in mine when i use the reg i dont get a knock but do see a big diff in power. also with the oil i use mobile one 5w30 and yes if you take it some place for your oil change its alot of money here in nj its just under 100 bucks for a mobile one oil change but i do it my self i buy a ac delco filter and the 5.1 quart jug of mobile one for 34 bucks and every once in a while they will have a rebate for like 6 bucks back if you mail in the card and wait 2 months for a 6 dollar check

 

Thanks for all the info. Next fill up will be premium and I'll see about that noise. It runs great, just want to get rid of that noise....also, on the oil changes, the Chevy Dealer down the road from my work charges $10 to change the oil. They use the standard Mobile 1, 5w30. If I want the synthetic I think the price goes to about $35, but that's still not bad. It's usually done during my lunch break and I don't have to get dirty .