So, as I mentioned in a couple of earlier posts, I just got a 2004 RX-8 with 51,000 miles. It's titanium gray, with the touring package and a manual transmission. According to the vehicle history report I nabbed, it's had only one owner. So far, I love it.

Anyway, I was hoping to get some advice about how to make it last as long as possible. Much like my father, I like to keep my things until they're collector items or until they are literally falling apart. Most likely, the RX-8 won't suddenly start increasing in price any time soon, but no matter whether it does or not, I want to keep my car in the best condition possible.

I tried to search for most of these, so if they've been answered, please forgive my ignorance. My database searching skills are random - sometimes I get exactly the results I'm looking for, and sometimes I use nonsensical keywords that come up with nothing.

So a few specific things:

1) I've read that 5w30 oil helps increase engine life - I was wondering if it would also void the 100k/8yr core engine extended warranty.

2) I've read about people using pre-mix in their fuel, too - what effects does that have? Would this fuel additive have roughly the same effects? If I start doing something like that, do I have to shut off the thing that spews normal motor oil into the engine?

3) My understanding about the carbon buildup in the engine is that driving like a maniac gets rid of the carbon, so it's actually healthy to drive a little insane - using high RPM to get to the speed limit faster than normal and stuff like that. Is it better to get up to 9k RPM gradually and just kinda drive at 9k for a while, or does going from 0-70 as quickly as possible and then jumping to 100+ when you need to pass people work just as well?

Those are really the only specific questions I have. Any other advice not covered by my questions about increasing my car's life span would be appreciated, too.

 

How about you don't jump to 100+ to pass people ever.

 

You don't need to be going 100+... or even 70, to redline. From the other posts already covering this, people are talking about driving at 7500+ rpm assuming the engine is warm. You can do that in a lower gear without even speeding. If you try to do that in sixth you'll be going 140mph or so, which is not smart on daytime city streets.

 

Good Luck, I plan on keeping the car for a long time too. I've had it for 4.5 yrs now.

 

Uh, sorry, that was my sense of humor trying to sound ... well ... humorous. Due to exaggeration. I do know how to drive. Also, I don't live anywhere near civilization. In order to be driving on daytime city streets, I'd have to spend about ... oh, a minimum of five hours on highways getting to the city, first.

I was intending to ask if dropping to third (to get around people who are doing 60ish in a 65) and then using the car's full power to speed up as quickly as I can is less than healthy. If it would be more healthy for me to just accelerate slowly (not using the car's power) to get to 9k RPM, then I'll start driving a bit nicer. That's all I meant.

 

Hi.

No, you don't have to drive like a maniac, nor should you.

If you are from a rural area, and are anywhere over 30, you should know about 2 stroke dirtbikes. If you are under 30, ask someone who has ridden 2 stroke dirtbikes....

The correlation is that 2 strokes have very little torque down low, and are (mostly) tuned so that they need to be "on the pipe" (at higher revs) to get the power, and avoid fouling sparkplugs from the over-rich oil/gas premix.

RX-8's are kind of like that. Mazda put a 9,000 RPM redline (when the engine, oil and transmission is nice and warm) on our cars because they are tuned to provide power at higher revs.

The secondary intake manifold ports, the secondary fuel injectors, and even the Variable Fresh Air Duct by the air filter only come on at high (for simplicity, let's say above 6,000 revs) revolutions.

In addition, RX cars are not (have really never been) designed for the dragstrip, or for maximum speed touring for that matter. They have been designed as sports cars - that accelerate and brake, and handle from corner-to-corner - better than almost anything else out there.

Given the above, up shifting when the revs get to 8,500 (or 9,000) will only drop the revs to 7,500 (or, 8,000) - this will keep all of the above-mentioned valves and injectors producing max power. Downshifting and hitting the apex of a corner at about 6,000 rpm, will mean that the engine is at that majic 7,500 rpm point when the car is through the corner and headed for the next straight.


Mechanically, all of the above valves (the APV, SSV, and VFAD) need to be exercised, or they may start to stick. As alnielsen said, the excess oil (and extra-rich fuel/air mixture) that is prevalent at lower revs will leave deposits in the combustion chambers and the lower intake manifold.

The throttle pedal was designed to be exercised through its maximum travel.

Periodically running the car as it was designed (canyon carving) at higher revs will 'solve' all of the problems that city-folk have with carbon and other gunk buildup. It will also remove buildup from those many times that we are forced to be Sheeple.

Note, that you can do this without ever (well, almost never) exceeding the speed limit.

Above all, have fun. And, be careful out there.

 

As long as you're putting maximum load on the engine in the higher revs, you'll be doing the engine a favor. As for me, I floor it in first gear, hit 42 *in a 35* and call it a day. I never really hit highways around here unless I'm traveling, and then my car is really feeling the burn

 

Redline in 2nd. Fun, good for your '8, and legal.

 

FWIW, cruising at 70 (usually the posted speed is 75) then accelerating 20 or 30 mph more to safely pass is nothing unusual in rural Colorado as far as a lot of highways are concerned. I've been in many situations where the flow of traffic cruises at about 90. But yeah, none of this is necessary to eliminate carbon buildup and state cops won't believe your excuse.

 

Redline in 1st, 2nd, and 3rd!