Fluid refill recommendations

[her97cobra]

I'm new and have a lot ot learn. I have a 97 Cobra, and am just wondering what brands you all use for Brake fluid, Tranny fluid etc. I read the post where it seems that Mobile/Castol full synthetic are a good choice for oil. What about Royal Purple? thanks in advance!

[ProfChaos]

I'm new and have a lot to learn. I have a '97 Cobra, and am just wondering what brands you all use for brake fluid, tranny fluid, etc. I read the post where it seems that Mobil/Castrol full synthetic are a good choice for oil. What about Royal Purple? thanks in advance!

Royal Purple is an excellent choice--as is AMSOIL--, though both tend to be a little more expensive than either Mobil 1 or Castrol fully-synthetic oils. (I prefer Mobil 1 Extended Performance (http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_Extended_Performance.aspx) 10W-30 over Castrol, and I prefer Royal Purple (http://www.royalpurple.com/motor-oil.html) over both. And, in my view, AMSOIL (http://www.amsoil.com) is, by far, the best choice in fully-synthetic oils.)

Once you make the switch to fully-synthetic oil, one thing that you do not want to do is to switch back-and-forth between synthetic and conventional oils: This can sometimes cause problems with oil seals leaking.

Personally, other than during the break-in period on a new or rebuilt engine, I would never run anything but fully-synthetic oil in a Cobra (and I would change it much more often than recommended by the oil manufacturer, just to be safe). Also, it is probably a pretty safe bet that if one buys a used Cobra, the car already has fully-synthetic oil in it. (Cobras can sometimes be very expensive to repair, so it is arguably a very good idea to hedge your bets in terms of component wear and high-mileage engine maintenance by running fully-synthetic fluids.)

cheers, :cheers:

--Professor Chaos

[her97cobra]

Thanks, Chaos, I am going to assume you mean synthetic for all fluids, not just oil? So then does Royal Purple produce the other fluids too such as brake fluid and tranny fluid? If not, what do you recommend for those? I haven't used them yet, but when I went to Checkers and autozone the other day I got synthetic brake fluid and tranny fluid which I can take back. They are both Valvoline syn power brands.

[SuperG]

Recently quite a few folks made the switch to RP including myself...so far I am quite happy. I changed the engine oil, tranny fluid, and rear gear oil.

The only non-RP fluids I have is the Power Steering fluid (Valvoline Syntech stuff) and the brakes. As far as brake fluid goes, I cannot remember what I am using...but it's more than 550-degree stuff since I hit the track from time to time...in between however, any decent brake fluid is fine since it's not lubricating parts...not supposed to anyway!

Here's a thread you might find interesting:

http://www.svtcobraclub.com/forums/showthread.php?t=14501&highlight=purple

[her97cobra]

Thanks SuperG, The article was interesting, I appreciate it. And thanks for the other answers too. Looks like I am going to try Royal Purple!

[SuperG]

Hey, the worst you are doing is putting a girly color into your Cobra!!

[flynfink]

Once you make the switch to fully-synthetic oil, one thing that you do not want to do is to switch back-and-forth between synthetic and conventional oils: This can sometimes cause problems with oil seals leaking.

Personally, other than during the break-in period on a new or rebuilt engine, cheers, :cheers:

--Professor Chaos


According to Mobil's website. both statements are myths. Changing oil from synth. to conventional or back will have no effect on seals. Also, there will be no difference in breaking and engine in with either. As stated, many HP engine manufacturers ship new with synth.

http://www.mobiloil.com/USA-English/MotorOil/Synthetics/Myths.aspx

I agree with running full synth. (I do in most of my stuff), but I vary the change interval is based usage. My 99 Cobra probably gets 4-6 K miles per year of mostly highway and backroad miles, I change it every spring. My MC's get changed every 3-4K.

The 3000 mile recommendation is an oil industry average. My GF drives her car 60 miles of interstate every work day and we change it every 5k or so. Now, if your driving 20 miles of stop and go on dusty roads, better go more ofter than 3000.. Synth. oil does not break down or looose viscosity.. It does, however get contaminated. I know some guys that change engine oil about every 12k miles, but they do change the filter every 3-4K and add what they lose in the change.

Lastly, I have RP in the trans and diff on all my cars. good stuff.. You many also want to look at syth. brake fluid.. It's not as corrosive not as hydroscopic as standard HD fluid and has a great boiling point.

As always, your mileage may vary.

[her97cobra]

Hey, the worst you are doing is putting a girly color into your Cobra!! HA HA! Considering I'm a girl, as if you couldn't tell by my questions, the girly color dosen't bother me!:D But thank goodness it's not pink!

[her97cobra]

Thanks flyinfink for your response as well, I've heard there are big debates on some sites about how often to change the synthetic oils. With my car having 39,000 miles now, and it's not a daily driver, I don't expect to rack up many miles per year. At least I don't plan too. But I have found I get a bit antsy when I haven't driven it for a couple days when the weather has been nice! :D

[ProfChaos]

Thanks, Chaos, I am going to assume you mean synthetic for all fluids, not just oil? So then does Royal Purple produce the other fluids too such as brake fluid and tranny fluid? If not, what do you recommend for those? I haven't used them yet, but when I went to Checkers and autozone the other day I got synthetic brake fluid and tranny fluid which I can take back. They are both Valvoline syn power brands.

My vote on transmission fluid, differential fluid, and brake fluid is that, if you are going to switch to synthetic, since these fluids are changed much less regularly than oil is changed, it just makes good sense to spend a little more to go for a much higher quality product, namely Royal Purple.

For example, I just spent over $3000 to have my engine rebuilt, including all new lifters. As a consequence, once the break-in period is over and I can remove the conventional break-in oil, I will never run anything other than AMSOIL 10W-30. Since I live in Florida where a car can take a real beating in the heat, I would rather pay the extra money to ensure prolonged engine-life: I am in no big hurry to go a through another engine-rebuilding ordeal...Trust me, getting a Cobra engine re-built tends to be a pain in the arse. :)

To answer another question, your transmission probably does not already have synthetic fluid in it (Ford recommends standard automatic transmission fluid [ATF] for the T-45 transmission in the '96-'98 Cobra), but as SuperG observes, many Cobra owners have chosen to switch to synthetic transmission fluid, and Royal Purple is a very good choice. For my part, I think that switching to Royal Purple transmission fluid (and differential fluid) is a capital idea, an idea that could, in the long run, save thousands of dollars in maintenance expenses.

Coincidentally, today, I paid $1100 to have my T-45 transmission rebuilt, including two new gear clusters. Consequently, even though I got 149K-miles out of the original transmission, I will still be switching to Royal Purple transmission fluid (synthetic ATF, I presume). I'm going for 300K-miles on this transmission. :thumbsup:

[her97cobra]

Thanks you so much ProfChaos for your detailed response. I was beginning to wonder if everyone left town or something. You answered my clutch question also, which I had posted in another thread, and no one had responded to. Let me also ask you this...as I'm trying to improve my driving skills...I am assuming the clutch in my 97 Cobra is stock, it's not the easiest clutch, and I was pushing the clutch to the floor to shift, well a fellow Mustang enthusiest told me that I could probably just push the clutch in an inch or two and it would engage. To my surprise it did. Now I can do this while just shifting on the street, but when turning or slowing I still go to the floor. The clutch has never made a grinding noise, but is shifting this way a bad thing? Or is it a matter of opinion?