I was wondering, since i live in a hot climate and all, i've been reading and its better for the engine to use a thicker grade oil compared to the recommended 5W-30 in the Owner's Manual. Anyway are there any dangers to running 20W-50 on a stock 96 LT1? btw: temperature here is usually above 85 F.

 

I really like Mobil 1 in the weight 0w40. In your type of climate, especially with some miles on the motor I do not think running 20w50 would hurt anything. However, you do reach a point of diminishing marginal returns- that is, going thicker will not help out any more. In fact you could see some slight losses in fuel economy because the engine will have to work harder to pump the 20w50 oil.

I think the most you really need is 10w40, but it's your choice.

 

i used 15W50 and it was fine in my car...but this was 2 trans am's ago..and it had 130k miles on it.

 

I swear by 15w 50.... If you saw how ahrd I ran my car... you would too.

 

If its always that hot then I guess youll be fine. The only bad thing about running thick oil as I see it is the initial fire the oil doesnt move around quite as fast and free. I like the M1 0w40 as well and have run it in the summer. But really if you drive your car in the city then its gonna get hot in the summer or the winter... it doesnt matter how cold or hot the air temp is because the oil still reaches 170ish degrees.

 

no real "dangers" unless its used oil or something. who makes the brand you are thinking about switching to? if its mobile 1, ive read that their oil tends to run a little bit thinner than most other oils anyways. ive been using their 15-50 blend with no problems. ive ran my motor with 15-50 for the entire 50k miles that i put on it before my last rebuild (was a new engine when i got it). during the rebuild, i took note of the cam bearings and such. all the bearing were immaculate. including the front bearings that reportedly get the most wear (i was still using the cam driven water pump at the time). so no problems at this end.

there is a viscosity limit, obviously. but i dont feel that 20-50 is a problem. i would probably stay with about a 40 max with anything other than mobile 1. but thats your call. unless some oil gurus want to step in and say otherwise. one of the only problems switching oils, that i know of, is switching a high mileage engine using dino oil to synthetics. and all that is is a problem from the synthetic detergents eating away at the dino residue and grime deposits that could expose potential leak areas that the dino oil kept sealed up.

 

well i was thinking of getting Pennzoil. If there really isnt any problem running the car with 20W-50 i guess i'll do it, its already pretty difficult to find 5W-30 in Panama without having to order it. oh yeah btw: my engine has 58k miles on it so i wouldnt classify it as high mileage...one other question: will the car hold up in bumper to bumper traffic? (happens every now and then).

 

Just so you know, if you run too thick an oil for the engine's clearances, you will drive up pumping & frictional losses and heat.

Also, with dino oil it's generally best to stay with a 20-point spread. (0w-20, 10w-30, etc.) IIRC, it has something to do with the amount of viscosity modifiers required to make the larger spread and the lifespan of those modifiers.

What I personally do is run the thinnest oil that will provide at least 10lbs of pressure at idle and at least 10psi/1000rpm.

You might be better served with, for instance; 10w-40 Mobil One. There are plenty of other synthetic brands out there and of course; there's nothing "wrong" with dino oil, but I personally feel more comfortable trusting my engine to synthetic. With extreme environmental conditions, in either direction, it's even more important.

By the way...
Do they still have those 30 foot tall marijuana trees down there?

 

i do 10w40 in winter 15w50 in summer

 

I would stay away from Pennzoil.

In my college chemistry class a few semesters ago, we did a whole study of the components of different oils and Pennzoil had the most dyes and the most parrafin (wax) and it was suprising how much you could get that oil to sludge up when it was placed under compression, heat, and rapid break down.

Castrol GTX and Valvoline did the best. Quaker State was the same oil as Pennzoil only it had alot less wax and dyes, yet performed the same.

That is just my $0.02 though....

But if you were doing synthetic then the info I just gave you was completely worthless

 

I ran Havoline 20w-50 from 132,000 to 270,000 and never had any problems with it.

 

Tear apart a motor thats run pennzoil for 100,000+ miles and you'll need to make a run to the bathroom.....avoid it.

 

Since it was a chemistry class and I know you diddnt actually run it through an engine, it wasnt a real life test since it was used out of application..I'd like to hear more about this though, My best friends dad has penzoil as a sponsor at a local dirt track in modified late model class. Only oil hes ever used, 12:1 compression carbed 400 small block.

 

Re: what are the dangers of running 20W-50?
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If ya want the best get Kendall GT1 from here:

http://www.amref.com/default.asp

This is the ORIGINAL formulation that has been used for a long time,not the new stuff they say is better.
:

 

thanks a lot guys. yea i will be running synthetic so no harm there right? also doing a full tune up: filters, spark plugs and wires. Any good shift kits for an A4?