oil weight question
 

Whats the best weight oil to put in a daily driver 90 GT? Since its spring now in NYC, i'm guessing 10w30 or 10w40? Any preference?

Also on a side note, I have a 72 challenger with a 340 bored 30 over, strickly used in summer for street driving/racing and occasional track time. Is 20w50 too thick? Any negatives? Thanks.

I'm guessing the '90 has a few miles on it. Personally, I prefer 10-40 in the summer as I feel it offers better protection when the temps are high. As far as your Chrysler, depends on bearing clearances; loose, the 20-50 if fine; tighter, as the factory built it, I would again use 10-40. I'm guessing you are running a 180 or so thermostat in this car. If it runs hot, 200F, you may want to consider the 20-50.

the 340 used to run hot with an electric fan so i switched to a flex fan and now temps stay at about 180-190. i changed the oil yesterday and threw in 20w50, now i'm thinking twice about it. not sure about the bearing clearences, engine work was done before i got it, but i have all the figures. what is considered "loose" or "tight"?

10-30 would be satisfactory unless you have an oil burning problem.

how about this one. I have an 87 LX with about 167000 miles under the belt. What do you think about using 20w-50 on it since I got it. I'm in Miami,FL so we see alot of hot weather. I have a 197 thermostat on it and a heavy duty clutch and new stock radiator and my stoch temp gauge never goes even near the half way mark. staying usually during the first and second marks after the first really thick one. Oil pressure usually fluctuates a little before the mid mark and a little after. I always warm up the car in the morning holding around 2000 rpms for about a minute or so. Any idears.........

Vic




PS need a tranny now excepting donations for the "I NEED A TREMEC FUND" =>

PSS aboslutely no smoking or burning or consuming of oil. just a minor leak. One quart every 2 weeks or so. it usually helps when I add a quart of kendal SAE 50 in between my monthly oil changes

My personal opinion, for normal driving, unless you have a problem with burning oil, no matter the mileage, I would still use 10-30. My last van had 126,000 miles on it when I sold it. It burned no oil to speak of, even on high speed road trips to Florida.

20/50w
 

[QUOTE]Originally posted by FiveORookie
how about this one. I have an 87 LX with about 167000 miles under the belt. What do you think about using 20w-50 on it since I got it. I'm in Miami,FL so we see alot of hot weather./QUOTE]

With the high mileage that you have, I'd definitely use 20/50 weight oil in your motor. You should burn less oil than with the 10/30w.