OIL FOR Z28 LT1

[Z28- LTI]

I have 70K miles on a 1994 Z28 LT1 engine. I never start the car less than 15 degrees F. It is a automatic and never reaches redline but is occasionly run hard over 6K RPMs. Question: what is the best oil and filter to run in this 'machine' ? I have been using the Mobil 1 5W30 and a Fram oil filter. My friend suggest that I switch to Mobil 1 0w40 and a K&N Gold filter. I have been considering a switch to Mobil 1 5w30 Extended Performance with the more additives. Suggestions please !

 

[KW]

I don't know where "home" is but the Mobil 1 0W40 would be a very good choice for your car as you see temps as low as 15 degrees.

 

[454MAG]

Mobil 1 0w40 is an excellent choice for your LT-1. I am currently running it in my 94 LT-1 formula with 225000 miles on the clock with a 10K mi OCI. I had previously mixed Mobil 1 10w30 and 15-50 in varying amounts thicker in summer thinner in winter and getting excellent results on uoa. I will probably thicken the 0-40 with some 15-50 this summer. I run AC pf35l filters but k+n is a good one. I would avoid 5-30 in the hot running LT-1. This car has had only M1 since new and has never had the valve covers off. JMO
Ted

 

[haley10]

I'm not an owner, but all the uoa evidence here seems to suggest that German Castrol 0w30 and Mobil 1 0W-40 give the best results. Either would be a better choice over the Mobil 1 5w30 in this engine.

I am not a fan of Fram oil filters. The K&N would be a better choice, imho.

Sounds like your friend knows what he's talking about. Personally, I'm a fan of the GC 0W-30.

 

[ruking77]

Well for sure they do not make it easy. Mobil also makes 0w30, 5w30, 10w30, 0w40, and in EP !!!

Does your LT1 also have the need for the GM4178 M standard?

I have 68,000 miles on a 2001 Z06 Corvette, with 15,000 mile OCI's on Mobil 1 5w30 and would have no concerns with also running in addition to the above weights, 5w40 T & S.

The truth however is 5w30 has worked pretty well. I also have used the AC Delco PF44 oil filter.

 

[Patman]

I got excellent oil analysis results using German Castrol 0w30 and a K&N HP3002 oil filter on my old 95 Firebird Formula (LT1 engine)

 

[Racerjk]

quote:

---

Originally posted by 454MAG:
Mobil 1 0w40 is an excellent choice for your LT-1. I am currently running it in my 94 LT-1 formula with 225000 miles on the clock with a 10K mi OCI. I had previously mixed Mobil 1 10w30 and 15-50 in varying amounts thicker in summer thinner in winter and getting excellent results on uoa. I will probably thicken the 0-40 with some 15-50 this summer. I run AC pf35l filters but k+n is a good one. I would avoid 5-30 in the hot running LT-1. This car has had only M1 since new and has never had the valve covers off. JMO
Ted

---

I just switched to 0w40 from a 3/2 Mobil 1 10w30 / Mobil 1 15w50 mix. I'm about 500 miles into the interval, and I love 0w40 so far. The engine is quieter at startup. The engine accelerates smoother also, especially in the upper rpm ranges.

Gas mileage is much improved as well. I have been driving slower due to the high gas prices these days, but I also have quite a bit of town driving on this tank. I usually get around 25 or so, but I think this will be from 26 to 28 mpg.
I'm impressed.

 

[mikemc]

Mobil 1 0w40 sounds like a good choice for that engine. I have no experience with K&N filters, I know AC/Delco and Purolator are good choices.