Jeepsqueak
NAXJA Forum User
Hello everybody. I was hoping to get the opinions of as many people as possible on reasonable (and hopefully cost-effective) methodologies for improving and maintaining the performance of your XJ. I've been inspired by the ridiculous amount of advertising suggesting that you could (if you add it all up with a calculator) double your MPG and add fifty ponies with a slew of products costing thousands of dollars. It strikes me as bullshit, and the mechanically inclined I know are generally a skeptical bunch when it comes to most of these products. Still, I'm not sure what to think about a lot of this. I definitely don't have a lot of mechanical knowledge, but I'm pretty sensible. I'm hoping to see what others have come across in their quest for answers. Here are a few in particular I was wondering about.
Fuel additives. I've heard from a few that certain fuel additives serve to keep things clean and will sometimes improve your fuel economy. I know there are dozens of these products, some claiming to be safe for your catalytic converters and O2 sensors and some not saying much at all. I've used fuel additives in other vehicles at times, and I have noticed, especially during highway driving, that the gas indeed seems to last a bit longer. Similar experiences? Arguments against?
Aftermarket or late-model XJ exhaust header. I'm not sure exactly what the issue was engineering-wise, but I've heard a lot of talk about how the pre-99 (I believe) XJ's came with a header which eventually would succumb to the pressure (particularly with the 4.0 HO?) and crack. Some have suggested that replacing it with a later-model XJ or Borla header will prevent the issue from occuring and improve the efficiency of the engine. What's everybody think? This seems credible to me at least from the standpoint of not having to deal with that specific problem every couple of years.
Less restrictive exhaust systems. I've heard what sound like strong arguments from both sides of the issue on this, but I'd still like to solicit people's experiences on the matter to learn more. Strong arguments for stock mufflers?
"Performance" distributor caps/rotors/plugs. It seems a lot of experienced wrenchers feel that the stock plugs are the best to use for a number of reasons, and that expensive "upgrade" plugs (like Bosch Platinums) are basically a waste of time. I haven't heard a lot of talk about after-market distributor caps, etc, yet. I understand a lot of people do homebrewed electrical mods, like widening the gauge of the battery terminal wire. I would love to hear from anybody who was into this sort of stuff.
Computer modification chips (e.g., Jet Phase I module). It seems to me that these devices mainly reconfigure the range in which the engine is performing at it's optimum. I'm not sure if they actually provide overall gains, or just basically shift around the bands in which the power is being delivered. Testimonials or tech stuff?
Synthetic oils (gearbox, diff., engine)? B&M Trick Shift? Rabbit's foot strapped to the spare? Rebuild your engine?
And basically, anything anybody wants to suggest or talk about on the matter of maintaining and caring for their XJ's engine. I'm sure many of these matters will vary depending on the engine you've got. I've read a lot of what's been posted here in the past on some of these matters -- a lot of very intelligent posters. I don't mean to stir the pot again, but I figured you can always opt out if you're tired of talking about it.
Thanks in advance for your thoughts!
Fuel additives. I've heard from a few that certain fuel additives serve to keep things clean and will sometimes improve your fuel economy. I know there are dozens of these products, some claiming to be safe for your catalytic converters and O2 sensors and some not saying much at all. I've used fuel additives in other vehicles at times, and I have noticed, especially during highway driving, that the gas indeed seems to last a bit longer. Similar experiences? Arguments against?
Aftermarket or late-model XJ exhaust header. I'm not sure exactly what the issue was engineering-wise, but I've heard a lot of talk about how the pre-99 (I believe) XJ's came with a header which eventually would succumb to the pressure (particularly with the 4.0 HO?) and crack. Some have suggested that replacing it with a later-model XJ or Borla header will prevent the issue from occuring and improve the efficiency of the engine. What's everybody think? This seems credible to me at least from the standpoint of not having to deal with that specific problem every couple of years.
Less restrictive exhaust systems. I've heard what sound like strong arguments from both sides of the issue on this, but I'd still like to solicit people's experiences on the matter to learn more. Strong arguments for stock mufflers?
"Performance" distributor caps/rotors/plugs. It seems a lot of experienced wrenchers feel that the stock plugs are the best to use for a number of reasons, and that expensive "upgrade" plugs (like Bosch Platinums) are basically a waste of time. I haven't heard a lot of talk about after-market distributor caps, etc, yet. I understand a lot of people do homebrewed electrical mods, like widening the gauge of the battery terminal wire. I would love to hear from anybody who was into this sort of stuff.
Computer modification chips (e.g., Jet Phase I module). It seems to me that these devices mainly reconfigure the range in which the engine is performing at it's optimum. I'm not sure if they actually provide overall gains, or just basically shift around the bands in which the power is being delivered. Testimonials or tech stuff?
Synthetic oils (gearbox, diff., engine)? B&M Trick Shift? Rabbit's foot strapped to the spare? Rebuild your engine?
And basically, anything anybody wants to suggest or talk about on the matter of maintaining and caring for their XJ's engine. I'm sure many of these matters will vary depending on the engine you've got. I've read a lot of what's been posted here in the past on some of these matters -- a lot of very intelligent posters. I don't mean to stir the pot again, but I figured you can always opt out if you're tired of talking about it.
Thanks in advance for your thoughts!
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