93 Prelude - Oil Choice

[92saturnsl2]

Picked up a used Prelude a couple weeks ago and have had a chance to put it through it's paces. Car has 217k, no major overhauls, so original engine, 5sp transmission, clutch, etc.

Engine runs strong but doesn't get the gas mileage it should. I'm averaging about 25mpg, so there may be some significant engine wear or compression loss. No noticeable oil consumption, passed emissions and safety just fine.

I'm wondering which oil I should use on this engine. It's the H23A1, non-VTEC. Previous owner appeared to use synthetic, as the sticker said Valvoline MaxLife Synthetic 10w30. Is it wise to use a thicker oil or synthetics on an older engine? Which weight/brand? Any suggestions would be appreciated.

 

[Quest]

compression test reading?

Q.

 

[ThirdeYe]

Honda recommends that the Prelude should use 5w30 for all climates, or 10w30 can also be used for warmer temperatures. I would keep using the Maxlife the previous owner used, personally. Either 5w30 or 10w30 would work. No need to go thicker if there's no noticeable consumption or leaks. 25mpg doesn't really seem that bad, is it a mix of highway/city driving? Or pure highway? Your foot usually has the biggest impact on gas mileage...

 

[92saturnsl2]

It's mostly city driving and I must admit I find it hard keeping the tach out of the 5000-6500 rpm range, there's just something about that exhaust note that a Honda H series makes.

I will do a compression test soon, what should I look for besides being even across all cylinders?

Any other oil or filter recommendations?

 

[rclint]

I have a 97 accord, v-tech 4 banger that gets 28 mpg. It used to get 34, I'm not sure where I started loosing gas mileage, if I remember correct I put a after market o2 sensor on and it has not got 34 since then....even with the bad 02 sensor it got above 30 mpg.

I can also tell my car is loosing power, at 208k I can live with that awhile longer. If I can get 300,000 out of it I will be happy... no major overhaul on it either, it has had the timing belt/water pump treatment and the radiator replaced as well. These are fine made automobiles, no upkeep at all.

I have run just about every kind of oil I can think of in this car, from diesel oil to synthetic, current fill is maxlife, have been using whatever is on sale.

 

[ThirdeYe]

25 sounds normal for city driving and slightly aggressive driving (5-6k RPMs). I bet if you took that on the highway and kept it between 55-70mpg, you'd see 30+ mpg. Also: Havoline has worked excellent in my Honda B18 motor... that's worth a look into as well.

 

[SevenBizzos]

I have a '94 Si with 155k. I'm using Maxlife 5w30 and a PureOne. My MPG is usually around a little over 28 but has hit 30 when I took it easy (it was tough). It's always nearly 20% highway, 60% 2-lane roads with periodic stops, and 20% traffic. Your mileage does seem a bit low and may need a look as to why.

They're good cars. I'm planning on getting 100k more out of mine.

 

[Jeffdc5]

25mpg sounds about right for the way you drive. I get 23 mpg city in my type-s when i rev to 8800 a lot according to my scanguage. on the highway i get 34 mpg doing 65. Valvoline maxlife is a great oil you should keep using it.

 

[askani79705]

I'd keep the Maxlife.

 

[ThirdeYe]

Originally Posted By: ThirdeYe
25 sounds normal for city driving and slightly aggressive driving (5-6k RPMs). I bet if you took that on the highway and kept it between 55-70mpg, you'd see 30+ mpg. Also: Havoline has worked excellent in my Honda B18 motor... that's worth a look into as well.


Sorry, I meant 55-70mph, not mpg. If only a Prelude could get that kind of gas mileage!

 

[92saturnsl2]

Thanks a bunch for the responses. I'm going out to do a compression test now and will know more. Probably not necessary, but with the spark plugs where they are, will probably be a 15 minute job.

I found the Maxlife Syn at Walmart yesterday in the 5w30 weight. Does 5w30 in the winter mos (sept - march) and 10w30 the rest sound okay?

Any OCI or filter suggestions? I was thinking 5k w/ a Napa Proselect. I bought a Bosch Premium for this next OCI but they are pricey.

 

[92saturnsl2]

Compression test results:

#1 = 235
#2 = 225
#3 = 214
#4 = 228

Test was done at WOT, ECU fuse unplugged to kill the injectors. Results seem a bit high to me, but I don't know what to expect from this engine. Please chime in.

 

[askani79705]

Originally Posted By: 92saturnsl2
Thanks a bunch for the responses. I'm going out to do a compression test now and will know more. Probably not necessary, but with the spark plugs where they are, will probably be a 15 minute job.

I found the Maxlife Syn at Walmart yesterday in the 5w30 weight. Does 5w30 in the winter mos (sept - march) and 10w30 the rest sound okay?

Any OCI or filter suggestions? I was thinking 5k w/ a Napa Proselect. I bought a Bosch Premium for this next OCI but they are pricey.


Yes on the oil,Yes on the filter,nothing wrong with Napa

 

[SevenBizzos]

With the Syn, you're probably looking at ~7k OCI with a good filter. I know Farm & Fleet had Mobil 1 filters at like $3.99 or something.

You'd know more with an analysis, but I think that's a good starting point.

In the interest of disclosure, I found some old receipts from winter gas usage on the car. MPG's bottomed out at 25.5 (with $3.39/gal Premium) but was usually a little over 27MPG. My last run was 28.3 (and yes I keep a log of every tank full). I think I was running the A/C for a bit.

 

[Dave Hess]

Quote:
if I remember correct I put a after market o2 sensor on and it has not got 34 since then....even with the bad 02 sensor it got above 30 mpg.


I hope you are not using a Bosch O2 sensor in that Honda, if so next time buy a Denso.
Did you check to see if your PCV valve is clogged with oily grime ?

 

[rclint]

Wow I almost forgot about this post

If I remember correctly it was a Bosh O2 sensor, and of course hind sights is always 20/20, however it has 240k on the clock now, so I hope I don't have to do another 02 sensor. Looking back I may have made a mistake on the posting of miles, or maybe I just drive a lot more than I thought I did, I have a long commute to work so it adds up quick. One not on Honda engines, and general performance/gas mileage is the use of NGK plugs, they work really good together, and I use the iridium. It may be just hype, but I have had excellent results.

I hope I don't get bashed for this, and I'm not bashing either, but as a general statement I don't care for Bosh products, the Bosh platinum plugs seems like the best thing at first, but after a few miles on them and from my experience the performance really drops.

Clint

 

[Geonerd]

In-town mileage is largely a matter of traffic light anticipation.

Look ahead to the next light (and the one beyond, if visible) and make your best guess as to when it will be green. If you're clearly going to miss it, ease off early. If traffic allows, drop the car into neutral and coast for a while. Alternately, there are times when investing a small amount of gas to speed you up will increase the odds of squeaking through before it goes red. Obviously, you've got to take into account traffic, practical speed limits, etc. Don't be an OCD Hypermiler Dork and go blocking traffic!

You won't get it right all the time, but you should be able to avoid genuine surprises and most hard stops. Consider the brake to be a fuel dump lever, since you'll need to burn gas to regain lost kinetic energy.

Another tactic is running the engine at it's most efficient RPM and throttle combination. http://images.google.com/images?q=bsfc chart
Most fixed-valve-timing engines have a peak efficiency island centered near 25~50% of redline and 50~80% throttle. With a manual transmission, you can force the engine to operate in this regime. When pulling away from lights or accelerating, short shift using moderate throttle. Once at your target speed, plonk it into 5th and cruise at lowest possible RPM.

Even more efficient is a continual series of pulse and glide operation. This is seldom practical in traffic, although the hardcore MPG dorks do so. They even turn the engine off during the glide phase. As you might imagine, this is just wonderful for the ignition switch, starter and engine...

Google for 'pulse and glide' if interested.

Anyway, and for FWLIW, I've got a 92 Accord 5spd with a very similar H22 lump. I can get mid 35s around town w/o being a public menace or ruining my car. Assuming the car is running well, you should be able to crack 30MPG w/o too much trouble.

As for the engine, I'd check the plugs first. This will give you a good idea of the mixture accuracy. http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

Also FWIW, I've been using M1 for the last 60K or so and the car seems to love it. 7~8K OCI. I had the valve cover off a while back - the guts were spotless and the cams looked nearly new. (No signs of wear, pitting, etc.)

-Moo

 

[tig1]

Originally Posted By: rclint
I have a 97 accord, v-tech 4 banger that gets 28 mpg. It used to get 34, I'm not sure where I started loosing gas mileage, if I remember correct I put a after market o2 sensor on and it has not got 34 since then....even with the bad 02 sensor it got above 30 mpg.

I can also tell my car is loosing power, at 208k I can live with that awhile longer. If I can get 300,000 out of it I will be happy... no major overhaul on it either, it has had the timing belt/water pump treatment and the radiator replaced as well. These are fine made automobiles, no upkeep at all.

I have run just about every kind of oil I can think of in this car, from diesel oil to synthetic, current fill is maxlife, have been using whatever is on sale.







Try cleaning your MAF sensor. This needs to be done as part of any tune up. Caution----- be careful how you do it. Good idea to Google { MAF sensor cleaning}.